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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
BOOK OF ABSTRACTS
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
EDITORIAL BOARD Organising Chairperson: Endarko
Scientific Programme & Abstract & Proceedings: Freddy H (Chair) Kwan Hoong Ng (co-chair) Hafiz Zin (Malaysia) Anchali Krisanachinda (Thailand) Johan Noor (Indonesia) James Lee (Singapura) Heru Prasetio (Indonesia)
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
TABLE OF CONTENTS
EDITORIAL BOARD .................................................................................................................... 1 TABLE OF CONTENTS................................................................................................................ 2 PREFACE ....................................................................................................................................... 3 Section I: Pleanary/Invited Speakers .............................................................................................. 4 Section II: Workshop on Radiotherapy, Workshop on Diagnostic Radiology, Workshop on Nuclear Medicine and Workshop on Biophysics ..................................................................... 12 Section III: ORAL PRESENTATION .......................................................................................... 32 ORAL PRESENTASI - RADIOTHERPY................................................................................ 32 ORAL PRESENTATION – DIAGNOSTIC RADIOLOGY .................................................... 59 ORAL PRESENTATION – NUCLEAR MEDICINE .............................................................. 84 ORAL PRESENTATION - BIOPHYSICS ............................................................................ 110 Section VII: POSTER PRESENTATION .................................................................................. 133 POSTER PRESENTATION - RADIOTHERPY.................................................................... 133 POSTER PRESENTATION – DIAGNOSTIC RADIOLOGY .............................................. 168 POSTER PRESENTATION – NUCLEAR MEDICINE ........................................................ 189 POSTER PRESENTATION - BIOPHYSICS ........................................................................ 193
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
PREFACE The 17th SEACOMP and 3rd PIT-FMB2019 conference were designed as a platform for exchanging ideas in Medical Physics among Medical Physics community in Indonesia and South East Asian. In addition, this conference also will be beneficial for updating information, sharing knowledge among of professionals, institutional/university researchers, regulators and medical physicists who working in various hospitals in Indonesia and Southeast Asia. In this conference, the latest developments of global Medical Physics will be presented by invited speakers who are researchers and Medical Physics practitioners. This is the second time Indonesia is given the honour to host the South-East Asia Congress of Medical Physics (SEACOMP) after year 2015. The congress is expected to attract more than 250 participants from the professions of medical physics, biomedical engineering, radiology, radiotherapy, nuclear medicine, radiation protection, biophysics, radiobiology and the related fields. The theme for this congress is “Improvement on Patient Care and Safety through the innovation in Medical Physics”. We have a comprehensive scientific programme including orations, talks by eminent speakers, oral paper presentations, poster presentations, panel discussions and some precongress workshops that cover most of the disciplines in medical physics, i.e., diagnostic and interventional radiology, nuclear medicine, radiotherapy, radiation protection, radiobiology, and new emerging techniques. This book of abstracts is divided into four fields, I) plenary/workshop/invited speakers' abstract 30 abstracts, II) presenters' abstract (radiotherapy) - 74 abstracts, III) presenters' abstract (Diagnstic radiology) - 44 abstracts, IV) presenters' abstract (Nuclear medicine & Education) – 21 abstracts and V) presenters' abstract (Biophysics) - 30 abstracts. A total of 199 abstracts are published in this 206-page book of abstracts.
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Section I: Pleanary/Invited Speakers
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
John Cameron Memorial Lecture State-of-the-art Continual Education for Medical Physicists: Experience from Europe's EUTEMPE-RX Courses Prof. Dr. Ir. Hilde Bosmans, Medical Imaging Research Center Universitair Ziekenhuis Leuven UZ Herestraat 49 3000 Leuven, Belgium [email protected]
Medical physics is a new science, with very broad topics and in steady evolution due to emerging technology. As obvious from the theme chosen for the conference, namely “Improvement on Patient Care and Safety through the innovation in Medical Physics”, medical physicists have a huge responsibility towards the patients and the medical teams using medical devices based on ionizing radiation. Medical physics education prepares the new generation of physicists for these tasks. Education can take several years and covers knowledge, skills and competences as listed in the ‘European Guidelines on the medical physics expert’, Radiation Protection 174. It is however impossible to make comprehensive and fully up to date courses on all aspects. In only a few countries, expertise can be found to train medical physicists to the expert level in all relevant domains; in the majority of countries, however, teachers are confined to sub domains only. Within the European Federation of Organizations of Medical Physicists (EFOMP), the initiative was taken to group the scattered expertise and create a series of course modules to bring medical physicists to EQF level 8. The project plans on ‘European teaching and education for medical physics experts in radiology’ (EUTEMPE-RX) got supported by the EU and 12 modules have been worked out. They are now in their 3rd run. The current modules cover medical physics in radiology and the team of KU Leuven (H. Bosmans et al.) is the coordinator. The course modules are unique, as they ensure that you gain new competences in a specific topic. There is at first an extensive online material that covers the fundamentals of the chosen topic. The course concludes with an onsite part that includes hands-on sessions, face-to-face teaching, site visits and in-depth discussion in small groups. Modern teaching tools are used and the group size is limited to 20 – 25 physicists. We will illustrate some of the educational particularities. Read more on www.eutempe-net.eu . Also Asian medical physicists are very welcome. The EU has travel grants available until Dec 2021 for strengthening a career in nuclear sciences. This includes medical physics. Please submit your grant application to https://plus.enen.eu/grants/
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Plenary Speaker Future Virtual Clinical Trials in Radionuclide Therapy Prof. Dr. Gerhard Glatting Universitatklinikum Ulm, Klinik fur Nuklearmedizin, Medizinische Strahlenphysik, AlberEinstein-Allee 238908, Ulm, Germany [email protected]
Clinical trials are performed in medical research to determine if a new treatment is safe and effective in patients. To improve the treatment often a standard treatment is compared to a new treatment with respect to higher effectiveness or less harmful side effects. In order to achieve valid results, a good hypothesis to be tested and strict organisation of any trial is a prerequisite. In order to achieve unequivocal results, a large number of patients is usually required. A clinical trial is therefore costly with respect to financial resources, patient burden and time to completion. Targeted radionuclide therapy (TRT) is a systemic treatment with tumour-seeking molecules labelled with short-range emitting radionuclides, e.g. alpha, beta and/or Auger particle emitters. When administered to the patient, the radiolabelled molecules accumulate at the targeted tumour cells. Due to the short-range emitting nuclides the tumour cells are then irradiated preferentially. Dose-response relationships for TRTs are either already known from former trials or can be predicted from trials in radiation oncology. For the latter case the dose-response relationship must be converted to account for the low dose-rate in TRTs. This can be done for example using the concept of the biologically effective dose (BED), which considers the competition between the damage due to the low dose-rate irradiation (based on the biokinetics of the radiopharmaceutical in the patient) and the repair-rate in organs. Therefore, two different treatments – having different dose-rates due to different radiopharmaceuticals or different pharmacokinetics due to a modulation of the pharmacokinetics of the same radiopharmaceutical – can be easily compared based on the corresponding BED values. Virtual patients are used to describe the pharmacokinetics: A virtual patient is a mathematical, e.g. a physiologically-based pharmacokinetic (PBPK)) model, with model parameter values defined by measurements of e.g. organ masses, volumes and biokinetics of a corresponding real patient. The addition of pharmacodynamics, based on a given doseresponse relationship, allows comparisons to be made in silico for different treatment options to determine the optimal treatment algorithm. Such virtual clinical trials will provide optimal hypotheses for real clinical trials and thus lead to a more cost-effective development of new treatments.
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Plenary Speaker Current status and next stage of radiomics Prof. Hidetaka Arimura, PhD Computer-aided Diagnosis and Radiotherapy laboratory Division of Medical Quantum Science, Department of Health Sciences Faculty of Medical Sciences, Kyushu University [email protected]
Radiomics is a field based on data science that massively and comprehensively analyzes big data of medical images to extract a large number of phenotypic features reflecting cancer traits (genotypic features), and explores the associations between the features and patients’ prognoses for precision medicine. It would be possible to make decisions of more appropriate treatment policies for patients by predicting their prognoses using statistical inference models with radiomic signatures obtained from pre-treatment images in cancer therapy. However, the author considers that there are three scientific and/or clinical problems in radiomics. The first problem is that the reason why several significant image features have associations with patients’ prognoses is unknown. The second problem is that how to use radiomic associations in decision-making of treatment policies is unknown. The third problem is that texture features could not necessarily characterize malignant tumors, because the features were originally developed for characterizing forests, farms, urban areas, etc., on remote sensing images of the Earth’s surface. Nevertheless, radiomics approaches could contribute to the cancer treatment for patients in the future. The author will describe the current status and next stage of radiomics in this lecture.
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Parallel Session Current status of medical exposure in CT examination and patient dose management Dr.Toshioh Fujibuchi Department of Health Sciences, Faculty of Medical Sciences, Kyushu University Maidashi, Higashi-ku, Fukuoka, [email protected]
In medical field, radiation use continues to increase. While medical use of radiation benefits patients, there are also health effects from exposure to radiation. Therefore, justification and optimization are required. Among medical exposures, CT examination has a high exposure dose per time. Therefore, medical staff have to examine carefully. In Japan, various efforts are under consideration to reduce radiation exposure by CT examination. A nationwide survey is underway to grasp the actual condition of CT medical examination. Promotion of use of diagnostic reference level is required. Each medical institution has established a dose management system to grasp the dose for each examination protocol of its own facility. WAZA-ARI web-based CT exposure calculation system available free of charge has been released (https://wazaari.nirs.qst.go.jp/en/index.html). In order to improve medical education, re-education of medical staff and renewal of knowledge are required. The government has established a system to provide information on exposure to CT examination in an easy-to-understand manner to the public. In particular, help families of pediatric patients make rational decisions regarding medical exposure.
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Parallel Session The Development of Nuclear Medicine in South East Asia and The Role of Nuclear Medicine Medical Physicist Prof. Dr. Anchali Krisanachinda Departement of Nuclear Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand [email protected] Nuclear Medicine had been started in 1950s in Thailand and Philippines. In Asia and Pacific Regions, Nuclear Medicine has a steep leap in recent years due to many factors including support from IAEA under RAS, TC projects, national projects, Expert Missions, collaboration among countries via multiple international organizations e.g. ARCCNM, AOFNMB, WFNMB and RCARO. The project in Thailand supported by IAEA together with RCARO was aimed to promote Nuclear Medicine in Neurology and Theranostics. Support was further enhanced by Nuclear Medicine Society of Thailand. Many activities including 2 National training courses had been set up in Nuclear Neurology, lectures in Nuclear Neurology and Theranostics in many scientific meetings and hands-on workshop in Theranostics. These intense enhancement measures resulted in a marked increase in numbers of Nuclear Medicine imaging in Nuclear Neurology and Theranostics in many Nuclear Medicine Centers in the recent 5 years with more and more centers to perform these sophisticated imaging and treatment. Other than Nuclear Medicine physicians, IAEA also supports development of Nuclear medical physicists, technologists, radiopharmacists and nurses. Thus, Nuclear Medicine development in Asia and Pacific Regions has an excellent development under IAEA and many organizations support. The more developed countries will have ability to help other countries in the region in the near future. The major role and responsibility of the clinically qualified medical physicist, CQMP in nuclear medicine are the installation design, technical specification, acceptance and commissioning of equipment, including the establishment of criteria for acceptable performance. The others are the radiation safety and protection of patients, staff and general public, patient internal dosimetry, optimization of the physical aspects of the diagnostic procedure, quality management of the physical and technical aspects of nuclear medicine and collaboration with other clinical professionals. CQMPs have the leading role in preparation of equipment specification according to the needs of nuclear medicine facility. Following the installation of new equipment, CQMPs are responsible for specifying the basic standards to be applied for the acceptance and subsequent commissioning. They ensure that all units and systems function according to their technical specifications and guide on any deviation of equipment performance from acceptable criteria. Strengthening nuclear medicine medical physicists in SEAFOMP could be accomplished in the next five years on the cooperation in clinical training, sharing the clinical supervisors in the region and create the quality management for the benefit of patient healthcare in Nuclear Medicine. 9
The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Parallel Session Clinical Training of Medical Physicists in Nuclear Medicine in South East Asia using IAEA AMPLE Prof. Dr. Anchali Krisanachinda Departement of Nuclear Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand, [email protected] The need for medical physicists is becoming more evident due to the increasing complexity of both treatment and diagnostic equipment coupled to the raising expectations of good health care in all parts of the world as well as the implementation of radiation protection and safety standards, however the supply of suitably qualified and trained personnel has not kept up with these developments and hence this shortage is worsening. Another important reason for this is the migration of promising physics professionals from developing countries to more developed countries where the recognition of the medical physicists is better established. The introduction of a clinical training program, to supplement academic qualifications has the dual purpose of providing skilled professionals for the developing country as well as providing standards that can be used to raise the recognition of medical physicists. An increasing number of countries graduate level courses in medical physics are offered by universities. The clinical in-service training component however is in many cases small or missing. This has resulted in incomplete preparation of the medical physicists to practice independently as important aspects of training cannot be completed in the university setting. A structured in-service clinical training program provides a better preparation for medical physicists to ensure that they are capable of independent, safe and effective practice. Such a program should reduce the total time needed for medical physicists, referred to as residents in these programs, to reach clinical competence and also to prepare them to undertake the more advanced methodologies which are being rapidly introduced in the specializations of medical physics. Relatively few countries in South-East Asia have developed national standards of clinical training, which are an essential part of ensuring high quality and consistent training throughout a country. IAEA involves in medical physics education and training and has developed AMPLE, Advanced Medical Physics Learning Environment on a CLP4NET Platform. A set of guides and material has been used in the clinical training of medical physicists specializing in radiation oncology, diagnostic radiology and nuclear medicine. Thailand started Clinical Training in Nuclear Medicine the first in SE in 2011. Two classes had been completed and the third one is in progress for Thai, and Myanmar residents. The first training in Malaysia was in 2018 in collaboration with Thai remote supervisors. 11 modules with 8 core modules were self-assessed by residents and clinical supervisors. Midterm and final assessment were set within the period of two years which IAEA sent an external assessor together with national assessors prior to the completion of the program. There are 12 Thai, 1 Myanmar successfully completed AMPLE-NM. They became clinically qualified medical physicists in nuclear medicine in Thailand and Myanmar.
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Parallel Session Heart Detection Sensor Based On Self Mixing Interferometry A. Rubiyanto, N.D. Ariyanti, Syamsudin, O. Seabuka, A. Zulfikar, N. Nasori, E. Endarko Department of physics, Faculty of Science, Institut Teknologi Sepuluh Nopember, Surabaya, 60111, Indonesia. Email: [email protected]
Abstract Measurement of heart rate detection based on self-mixing interferometry has been done by using phase modulation with Fabry-Perot interferometry technique. The device consists of a diode laser with a wavelength of 785 nm which integrated with an optical detector, a laser driver as a laser pump, a mirror as a target vibrated by simulating the heart signal from the ECG generator. Characterization as a heart rate detection by variating frequency of 10 - 80 Hz generates feedback at a frequency of 50 Hz. The results of heart rate detection research based on self-mixing interferometry show that the higher of the frequency given to the audio amplifier, the amplitude value at the point Q and S at the heart signal will be lower.
Keywords: vibration sensor, self-mixing interferometry, heart signal, and ECG generator.
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Section II: Workshop on Radiotherapy, Workshop on Diagnostic Radiology, Workshop on Nuclear Medicine and Workshop on Biophysics
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Workshop on Radiotherapy Comprehensive Quality Assurance Impact in Radiotherapy Dr. James Cl Lee Department of Radiotherapy National Cancer Center of Singapore [email protected] Quality assurance is a critical aspect of Radiotherapy to ensure safety and integrity of the RT machines to treat our patients. Standard QA is performed regularly on various key RT devices by a medical physicist. For treatment delivery, we have various machines ranging from various types of LINACs to Brachytherapy remote afterloaders. For imaging there is CT Sim, PET-CT and also MR Sim. For IGRT, we have portal imaging and CBCT. External audits like IAEA dose audits can also be performed as a form of QA. QA practices continue to change and adapt with new technologies. Emerging use of surface guided RT and motion management devices also adds to the complex demands of RT QA. In addition, treatment planning systems have also seen changes with advanced features like deformable registration and dose calculation algorithms. It is also important that a physics QA should be in place for end-to-end testing to check the entire RT workflow, from imaging to planning and treatment delivery. This lecture will focus attention on a few key areas of modern RT QA and related dose audits. They are: 1) End-to-end testing (RT workflow commissioning and QA) 2) LINAC-TPS Annual QA (a new paradigm for Annual QA) 3) Dynamic MLC QA (VMAT and IMRT) 4) Log file QA (Patient specific monitoring QA) 5) Dose QA audit (IAEA and others) This lecture hopes to challenge us to move beyond standard RT QA as practiced today and to consider internal and external means of QA and audits to ensure a more comprehensive and safe RT program for the centre.
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Workshop on Radiotherapy
Computational and Calculation of dose in Advance Technique Radiotherapy Wahyu Edy Wibowo Rumah sakit Dr Cipto Mangunkusumo, Jalan diponegoro no.71, Jakarta pusat, 10430 [email protected]
Algorithm of dose calculation is a unique, critical, and complex component of radiotherapy treatment planning software. It is used to calculate the absorbed dose distribution of the patient by using the assistance of beam modeling. Nowadays, there are three types of dose calculation algorithms: correction-based, model-based, and principle-based. While each type has its own pro’s and con’s, Acuros, the principle-based algorithm, is proven to be the most superior compared to the others. As for the next steps, the biological equivalent dose based algorithm should be researched and algorithm’s clinical issues (buildup region dose, dose in the interface, and tumor in highly heterogeneous location) should be addressed.
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Workshop on Radiotherapy Patient safety issue in advance technique radiotherapy Ikhsan Bagatondi Nasution Chief Medical Physicist, Murni Teguh Memorial Hospital Jl. Jawa No.2, Gg. Buntu, Kec. Medan Tim., Kota Medan, Sumatera Utara 20231
Background This study was designed to make comparation of the quality assurance results (QA) of two dosimetry devices used for intensity volumetric modulation arc therapy (VMAT), Stereotactic body radiation therapy (SBRT), Intensity modulation radiation therapy (IMRT) in Murni Teguh Hospital, Medan-Indonesia as the implementation of patient safety. Materials and methods. A comparison of plan fields from two selected patients from each advanced technique radiation therapy (VMAT,IMRT,SBRT) followed by irradiation to the Dolphin online verification monitoring (IBA), ion space array (MatriXX). The dosage measured from the two dosimetry devices was compared with the dose calculated by the treatment planning system of the MonacoElekta. The passing rates of the two dosimetric tools were calculated using the gamma index method, using as criteria a dose difference of 3% and a distance-to-agreement of 3 mm. Results The QA results based on Dolphin and MatriXX showed good agreement, with average passing rates meet the requirement above 97 percent respectively. This QA methode is a part of patient safety in advance technique radiotherapy. Conclusions The selection of quality assurance tools depend on advanced techniques in radiotherapy. The passing rates should depend on the inter-comparisons of dosimetric tools if more than one dosimetric tool is used for patient specific QA.
Keywords: Volumetric modulated Arc Therapy, SBRT, intensity modulated radiation therapy, quality assurance, dosimetric tool, gamma index
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Workshop on Radiotherapy Recent Methods for Patient-Specific IMRT Treatment Verification Hafiz M Zin University Lecturer / Medical Physicist, Universiti Sains Malaysia IMRT delivers highly conformal photon beam to the tumour while sparing normal tissues. This is achieved by modulating radiotherapy treatment parameters especially the multileaf collimators (MLCs). The complexity of the treatment delivery requires patient specific pre-treatment verification to identify any discrepancies between the planned and delivered radiation dose distribution. This talk will give an overview of methods and tools that can be used to perform the absolute dose verification, and the expected agreement levels achievable between the prescribed and the delivered dose. Understanding of the metrics used to assess the agreement level such as gamma analysis is also important. The talk also will focus on recent techniques currently being developed to assess not only the IMRT dose but also the performance of linac delivery parameters that are vendor dependant. This assessment can give insight into the interpretation of the metrics measured during patient specific treatment verification QA.
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Workshop on Radiotherapy AAPM TG-100: Application of Risk Analysis Methods to Radiation Therapy Quality Management Cheng Saw, PhD, FAAPM Director, Medical Physics at Northeast Radiation Oncology Centers (NROC), Harrisburg, Pennsylvania, Hospital & Health Care, [email protected]
Modern radiation therapy processes are highly technical involving a number of different sophisticated equipment that is linked through digital networks to obtain patient information, plan treatment, and deliver the radiation treatment. These highly technical tasks increase the complexity of modern radiation therapy and pose challenges to the traditional prescriptive quality management (QM) methods. These prescriptive guidelines have traditionally focused on monitoring all aspects of the functional performance of the radiation therapy equipment by comparing parameters against tolerances set at strict but achievable values. Many errors that occur in radiation oncology are not due to failures in devices and software but rather on the failures in workflow and process. A systematic understanding of the likelihood and clinical impact of possible failures throughout a course of radiation therapy is needed not only to utilize limited QA resources efficiently but to produce maximum safety and quality of patient care. Task Group (TG) 100 of the American Association of Medical Physicists in Medicine (AAPM) has taken a broad view of these issues and has developed a framework for designing QM activities, based on estimates of the probability of identified failures and their clinical outcome through the radiation therapy planning and delivery process. The TG-100 has chosen a specific radiotherapy process required for “intensity modulated radiation therapy (IMRT) as a case study. The goal of this TG100 is to apply modern risk-based analysis techniques to this complex radiation therapy process in order to demonstrate to the radiation therapy community that such techniques may help identify more effective and efficient ways to enhance the safety and quality of the radiation therapy processes. TG-100 generated by consensus an example quality management program strategy for the IMRT process performed at the institution of one of the authors. The report by TG-100 describes the methodology and nomenclature developed, presents the process maps, FMEA, fault trees, and QA programs developed, and makes suggestions on how this information could be used in the clinic. The learning objectives of this presentation are to appreciate the underlying philosophy of TG-100 and to gain a brief overview on risk-based tools.
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Workshop on Diagnostic Radiology Optimization in Diagnostic Radiology: The Big Picture Prof. Dr. Ir. Hilde Bosmans, Medical Imaging Research Center Universitair Ziekenhuis Leuven UZ Herestraat 49 3000 Leuven, Belgium [email protected]
‘Optimization in radiology’ is the most relevant task for the medical physicist in radiology. It is however very challenging and requires a continuous (research) effort. In essence, x-ray dose and the performance that can be obtained with an imaging system have to be balanced. A 3-step process is then involved: understand the factors determining dose and performance, perform measurements to assess the situation and then improve this situation if needed. Several stages can be distinguished: (1) Define the radiological task of interest (2) Determine a critical structure representative for the task of interest (3) Make a test object or test set that allows to test the appearance of the critical structure (4) Acquire a series of different acquisitions and determine the appearance quality of the critical structure (5) Determine the radiation induced detriment in terms of either organ dose or effective dose (6) Balance performance and quality (professional judgement) For the whole medical physics community to learn from it, (1) Automate performance and dose measurements (2) Make it a procedure (3) Repeat on more systems and publish the data The whole procedure is more easy when performance and x-ray detriment are well defined. As an example, in breast cancer screening, performance is expressed and measured in terms of the fraction of screen detected cancers smaller than 1cm, while detriment is expressed in terms of mean glandular dose (with new approaches being discussed up to today). Centrally organized population screening of any type (breast cancer, lung cancer, colon cancer, …) normally registers relevant performance data, while this is not the case in general radiology, making the measurements of performance more difficult. As for radiation detriment, effective dose is still often used. We will illustrate optimization in digital mammography, chest x-ray exams in premature babies and abdominal CT. We will explain the advantages of organizing optimization with the work-out of a Monte Carlo simulation platform, tools to measure technical quality, access to test object manufacturing and computer algorithms to measure detectability. Optimization is a continuous project, with new equipment and emerging applications or new patient groups showing up every day. The most important first step is probably the communication with the medical teams to set the scene. 18
The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Workshop on Diagnostic Radiology Multimodality molecular imaging: Paving the way for personalized medicine Prof. Habib Zaidi1,2,3 1
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Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, Switzerland Department of Nuclear Medicine and Molecular Imaging, University of Groningen, The Netherlands 3
Department of Nuclear Medicine, University of Southern Denmark, Odense, Denmark Email: [email protected], Web: http://pinlab.hcuge.ch/
Early diagnosis and therapy increasingly operate at the cellular, molecular or even at the genetic level. As diagnostic techniques transition from the systems to the molecular level, the role of multimodality molecular imaging becomes increasingly important. Positron emission tomography (PET), x-ray computed tomography (CT) and magnetic resonance imaging (MRI) are powerful techniques for in vivo imaging. The inability of PET to provide anatomical information is a major limitation of standalone PET systems. Combining PET and CT proved to be clinically relevant and successfully reduced this limitation by providing the anatomical information required for localization of metabolic abnormalities. However, this technology still lacks the excellent softtissue contrast provided by MRI. Standalone MRI systems reveal structure and function, but cannot provide insight into the physiology and/or the pathology at the molecular level. The combination of PET and MRI, enabling truly simultaneous acquisition, bridges the gap between molecular and systems diagnosis. MRI and PET offer richly complementary functionality and sensitivity; fusion into a combined system offering simultaneous acquisition will capitalize the strengths of each, providing a hybrid technology that is greatly superior to the sum of its parts. However, the technology suffers from a number of drawbacks that will be discussed in this lecture. This talk also reflects the tremendous increase in interest in quantitative molecular imaging using PET as both clinical and research imaging modality in the past decade. It offers a brief overview of the entire range of quantitative PET imaging from basic principles to various steps required for obtaining quantitatively accurate data from dedicated standalone PET and combined PET/CT and PET/MR systems including algorithms used to correct for physical degrading factors and to quantify tracer uptake and volume for radiation therapy treatment planning. Future opportunities and the challenges facing the adoption of multimodality imaging technologies and their role in biomedical research will also be addressed. 19
The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Workshop on Diagnostic Radiology Assessing Image Quality in Mammography: an overview
Kristina Tri Wigati, M.Si Departemen Fisika, UI [email protected] Mammographic images involve two fundamental aspects: physical and clinical. The first aspect relates to the physical characteristics of the breast, the x-ray beam and the imaging chain in terms of its resolution, contrast and noise. The clinical aspect relates to a specific diagnostic task, such as the discernment of subtle microcalcifications, mass boundaries or architectural distortions from normal breast tissue structures. In assessing image quality, three components are involved: the actual image, the image assessor and the assessment technique. Assessments by medical physicists ideally use a phantom that truly mimics the breast anatomy that is imaged; it can be a physical phantom or a virtual one. The definition of the ideal phantom properties and the critical (detection) tasks, remains a challenging investigation. In terms of image assessor, the assessment of image quality can be divided into two approaches: subjective and objective. Subjective assessment is based on the perceptual assessment by a human observer, while objective assessment is assessed by computational methods, such as ‘model observers’. Subjective assessment is expensive, time consuming and requires a large number of people. Designing model observers to be consistent with subjective assessment is therefore an ultimate goal of many studies today. Regarding the selection of the assessment technique, reason behind the assessment should be considered, which could be to perform specific clinical tasks (performance), optimization, or to track changes via routine quality control, either performed by real or virtual study. This review is aimed to present the various methods implemented in assessing image quality particularly for 2D digital mammography applications. In assessing physical aspects, two methods are currently applied: test object evaluations (e.g. CDMAM phantom) and Fourier based analysis (MTF, NNPS, DQE). These methods can be applied for assessing the whole system, or specific components, such as detector performance. In assessing clinical aspects, task-based evaluation paradigms, namely Receiver Operating Characteristics (ROC), Visual Grading Analysis (VGA) or M-Alternative Forced Choice (M-AFC) are applied, either performed by humans or model observers. These two aspects of image quality are discussed, as well as the practical implementation of the European Guidelines in assessing image quality.
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Workshop on Diagnostic Radiology Approaches to strengthening justification of medical exposure in diagnostic imaging Ola Holmberg, Ph.D Head, Radiation Protection of Patients Unit Radiation Safety & Monitoring Section Division of Radiation, Transport and Waste Safety, Department of Nuclear Safety & Security, International Atomic Energy Agency, Vienna International Centre, PO Box 100, 1400 Vienna, Austria [email protected] Patients subjected to medical exposure need to be protected from unnecessary and unintended exposure. Unnecessary exposure of patients can arise from medical radiation procedures that are not justified for a certain type of use; application of procedures that are not justified for a certain individual’s condition; and medical exposures that are not appropriately optimized for the situation in which they are used, leading to unnecessary risks due to stochastic effects without the appropriate level of benefit. Over the last decades, there has been much progress in the area of optimization, but progress in the area of justification has been progressing more slowly. Authoritative sources suggest that a substantial fraction of radiological examinations may be inappropriate, from 20% to 50% in some areas. Key practical issues to the effective implementation of justification are first, the means of ensuring that those referred for radiological examinations really need them, second, auditing of the effectiveness of referrals and related processes and third, effectively communicating radiation risks to the relevant persons involved. The International Atomic Energy Agency, in cooperation with the World Health Organization, has over a number of years been systematically addressing the strengthening of justification of medical exposure in diagnostic imaging. Outcomes of this work has been e.g. the AAA Campaign which advocates actions to take in relation to Awareness, Appropriateness and Audit; the highlighting of the justification issue within the Bonn Call for Action; and the series of technical meetings and scientific articles on clinical imaging guidelines, guiding health professionals, mainly radiologists and referring physicians, as well as regulators. These approaches will be discussed, together with what the potential role of a medical physicist can be in this context.
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Workshop on Diagnostic Radiology Technical Image Quality Assessment in CT Choirul Anam Departemen Fisika, Universitas Diponegoro This talk will discuss a technical image quality assessment in computed tomography (CT). There are a number of parameters to assess image quality in CT, including: image noise, spatial resolution, consistency and linearity of CT number, low contrast detectability, and so on. However, due to limited time provided by the committee, this talk will only focus on the discussion on technical assessment of the noise and spatial resolution. The simplest technique to determine the noise is by calculating the standard deviation (SD) in the region of interest (ROI) selected manually in a specific area or in the most homogeneous region. The next technique is an automated calculation of the noise, which is by calculating SD values for every pixel with its neighboring pixel values in an image to obtain the standard deviation map (SDM), and the noise is determined as the SD value at the highest frequency from a SDM histogram. The most comprehensive noise representation is by the noise power spectrum (NPS), and it can be carried out both manually and automatically. While a simplest technique for the spatial resolution is by using visual observation to an image of the line pair phantom. For a more comprehensive approach, the spatial resolution of an image is characterized using a modulation transfer function (MTF). The MTF itself is obtained as a Fourier transformation from the line spread function (LSF). The LSF can be obtained directly from the image or it is calculated as an averaging process of the point spread function (PSF) or it is obtained as a differentiation process from the edge spread function (ESF). In addition, MTF can also be calculated directly from the line pair phantom. Moreover, MTF can also be obtained using fitting techniques, from both LSF and ESF. This presentation will practically explain various methods to obtain the noise magnitude and spatial resolution as the most important image quality parameter in CT.
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Workshop on Nuclear Medicine Patient Safety and Optimization of Medical Exposure in Diagnostic Nuclear Medicine Procedures Prof. Dr. Anchali Krisanachinda Departement of Nuclear Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand [email protected] This lecture starts by discussing the BSS requirements regarding technical optimization in diagnostic nuclear medicine and to define the relation between equipment performance and optimization principles. The following parts should describe the function, the operational considerations and the quality control of the different types of equipment used in nuclear medicine: Activity meter and calibration, Probes and counters, equipment for morphological and functional studies: SPECT, PET. The important part for nuclear medicine medical physicist is a detailed explanation of the MIRD concept of dose calculations, defining parameters such as absorbed fraction and cumulated activity. Then the concept of ‘Potential exposure’ contains the basic principles of safety assessment in order to identify the potential exposures in the handling and use of unsealed sources for diagnosis and therapy. Examples of accidents and incidents and discussion of the actions that should be taken.
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Workshop on Nuclear Medicine Radiation Protection of Patient in Biomedical research – Drug Development Dr. Deni Hardiansyah Postdoc scholar and staff Pharmaceutical sciences Department, College of Pharmacy, University of Kentucky 987 S. Limestone, Lexington KY, USA [email protected]
Pharmaceutical drugs have come to a long and complicated way to get into the market. After understanding the process of disease and formulating pathways to target them, scientists perform a screening of more than thousands of drugs candidate to get a lead compound that can act to this target. The lead compounds from this discovery stage are tested and developed in the drug development process before bringing them to the market. The drug development process is divided into several steps such as pre-clinical studies in animals and clinical studies in human subjects. In this workshop, we will discuss in brief the overview of the drug development process in the industry and how mathematical models, such as traditional compartment model or physiologically based pharmacokinetic (PBPK) models, are used to report/predict the ADME mechanism of the drugs based on their PKPD data. There will be two different drugs on the discussion: nonradioactive drugs (ND) and radioactive drugs, e.g. Radiopharmaceuticals (RPs). RPs are a unique species of pharmaceuticals containing both a drug and a radionuclide, which is widely used to diagnose/treat cancer in nuclear medicine. Several examples of drug development of ND and RPs especially for the first-dose estimation and its impact on nuclear medicine will also be discussed.
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Workshop on Nuclear Medicine Patient Safety and Optimization of Medical Exposure in Therapeutical Procedures Prof. Dr. Gerhard Glatting Universitatklinikum Ulm, Klinik fur Nuklearmedizin, Medizinische Strahlenphysik, AlberEinstein-Allee 238908, Ulm, Germany [email protected] Targeted radionuclide therapy performed in nuclear medicine departments is a systemic treatment like chemotherapy: Radiolabelled ligands are administered to the patient which accumulate at or in the targeted tumour cells. The ligands are labelled with short-range emitting radionuclides, i.e. alpha, beta and/or Auger particle emitters. Due to the accumulation the tumour cells are irradiated preferentially. Nevertheless, the irradiation of organs at risk and of the remainder of body – to preserve their function and to reduce secondary cancers – should be minimized while still conferring the prescribed dose to the tumour. In most cases, treatment planning is not performed on an individual basis, but with a standard activity, which was determined based on an activity escalation trial (similar to chemotherapy). Therefore, inter-patient variabilities with respect to e.g. pharmacokinetics and radiation sensitivity are neglected. This results in under- and over-treatment of patients resulting in less cures and more adverse effects than in an optimised individual treatment. According to the MIRD scheme there are two main contributors to the absorbed dose distribution in the patient: (1) the pharmacokinetics of the radiolabelled ligand (time-integrated activity coefficients (TIACs)) and (2) the masses and locations of organs (S values). As the S values of the individual patients cannot be changed easily, for an optimised medical exposure with ionizing radiation the pharmacokinetics must be adjusted individually. For the individual optimisation any prior knowledge about the patient can be used: This can be very basic like normalising the activity to the total-body weight or the body surface area, or it can include general anatomical, (patho)physiological and radiobiological knowledge about the treated patients, the disease and the used radioligand. Examples and the advantages for such sophisticated individualized treatment planning are presented for radioimmunotherapy (RIT), peptide-receptor radionuclide therapy (PRRT) and prostate-specific membrane antigen (PSMA)-specific radioligand therapy.
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Workshop on Nuclear Medicine Radiation Safety in Nuclear Medicine Facility Nur Rahmah Hidayati Center of Safety Technology and Radiation Technology National Nuclear Energy Agency (BATAN) Jakarta, Indonesia [email protected]
The number of nuclear medicine facilities in the world has been predicted to grow 7.6% by 2024. This means there will be more unsealed radioactive source will be utilized in the near future, and more radiation exposure will be generated from nuclear medicine facility. Following the publication of GSR Part 3 as the new Basic Safety Standard in Ionizing Radiation, IAEA has published a Specific Safety Guide regarding Radiation Protection and Safety in Medical Uses of Ionizing Radiation in the late of 2018. The guide provides recommendations and guidance for the safe use of radiation in medicine, including nuclear medicine practices. In general, the goal of the specific safety guide is to provide the recommendation to protect worker, people and the environment from the radiation risk. Hence, to achieve the goal, justification, limitation and optimization are the three radiation protection principles should be implemented in technical, clinical and practical aspects, starting from the designing the facility, the arrangement of radiation protection program, consideration for radiation exposure for patients, comforters and public in the case of radionuclide therapy. Moreover, special attention also has been focused on the possible emergency situation which may exist, such as clinical emergency for patients and the death of patient after radionuclide therapy.
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Workshop on Biophysics Interaction Mechanism of Non-Ionizing EMF with Living Tissues: Principles and Applications Dr. Warsito P. Taruno Center for Tomography Research C-Tech Labs Edwar Technology, Tangerang, Indonesia [email protected]
Non-ionizing electro-magnetic field (EMF) has become more popular in recent years for development of new method in combating cancers based on bio-physic interaction with living cells/tissues. In this presentation some newest EMF techniques will be reviewed, including electric field technique (tumor treating field, TTF), hyperthermia, radio wave therapy and electrocapacitive cancer therapy (ECCT). Especially, the ECCT that has been developed in Indonesia in the last 10 years will be described in depth, covering the principles, techniques, outcomes and issues. The ECCT is based on polarization interaction of cancer cells and tissues surrounding the cancerous mass with applied electro-static fields. The electro-static pulses disrupt the electro-static ordering within the cancer cell during cell split, preventing the chromosomes to separate properly, and at last causing the cell to self-destruction. The fundamental mechanism and basic principles of the electric field interaction will be specially described. Some results on in vitro and in vivo tests, as well as recent clinical trial results will be highlighted, along with real time monitoring system of treatment progress using electrical capacitance volume tomography (ECVT) imaging will be introduced.
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Workshop on Biophysics FIBER OPTIC SENSOR FOR BIOMEDICAL APPLICATIONS M.Yasin, Y. G. Y. Yhuwana and Suharingsih Department of Physics, Faculty of Science and Technology, Airlangga University, Surabaya (60115), Indonesia, [email protected] The design, experimentation and performance of fiber optic sensor using bundled probe and based on fiber displacement sensor and SMS (singlemode-multimode-singlemode) fiber structure for the measurement of amplitude and frequency of heartbeat signal is demonstrated. The displacement sensor consists of fiber optic transmitter, fiber optic bundled probe and photodiode detector and an artificial heartbeat signal is used in the testing. The sensitivity of the fiber displacement sensor is obtained at 0.002 mV/μm and thus it is capable of measuring heartbeat from 50 bpm to 300 bpm with linearity more than 99%. Using SMS fiber structure, The range of heartbeat measurement from 50 to 300 bpm for FOS and from 50 to 200 bpm. The simplicity of the design and the low cost of the fabrication make it suitable for real field applications.
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Workshop on Biophysics Flame Spray Coating Hydroxyapatite into Metal Implants Y W Sari1,*, M Permatasari1, and G E Timuda2 1
Department of Physics, Faculty of Mathematics and Natural Sciences, IPB University (Bogor Agricultural University), Indonesia, 2 Research Centre for Physics, Indonesian Institute of Science, Indonesia [email protected]
Metal implants are very widely used for implantation due to their advantages in mechanical properties, namely durability and strength. However, the use of metal as implants has several drawbacks, including the lack of osteointegration in the implant, and the corrosive effects of metals in biological fluids along with cyclic loads. Modification of metal implant surfaces with bioactive layers is expected to overcome these issues. Specifically, hydroxyapatite (HA) coating on the Steinless Steel (SS 316L) substrate is aimed to improve biocompatibility, osteochonductivity and bone bioactivity. Thermal spraying is a method that commonly used in coating HA into SS316L substrates. In this study, we applied flame spray coating for coating SS316L with HA. The HA which has been synthesized and has a size below 100 μm is placed in the chamber contained in the flame spray coating tool, then sprayed at a distance of 10, 20 and 30 cm with a gas pressure of 1, 2, and 3 bars. XRD and SEM-EDS were carried out to determine the phase formed, the morphology and presence of pores of HA coated substrates. The results obtained in this study show that coating HA on a bone implant substrate (SS316L) may increase the osteochonductivity level due to the pore formation.
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Workshop on Biophysics MCell – A Monte Carlo Simulation for Biological System A. Sutresno1,2, F. Haryanto1, S. Viridi1, I. Arif1 1
Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Bandung, West Java, 40132, Indonesia
2
Faculty of Science and Mathematics, Universitas Kristen Satya Wacana, Central Java, 50711, Indonesia
MCell (Monte Carlo Cell) is a program that uses spatially realistic 3-D cellular models and specialized Monte Carlo algorithms to simulate the movements and reactions of molecules within and between cells. MCell requires other software to visualize the models which are a blender and Cell Blender software. All software cans operation in all operating system and user-friendly to use. The site provides a good introduction to researchers interested in using Monte Carlo Simulations (a random number based simulation method, with the physical process simulated directly by sampling a probability distribution function) to answer a question in cellular physiology and structure. MC methods replace voxels and set of differential equation with stochastic molecular events simulated directly within the reconstructed volume of tissue. Individual ligand molecules diffuse by means of random walk movements, which reproduce net displacements that in reality would arise from Brownian motion. Movement trajectories can be reflected from arbitrary surfaces that represent cell and organelle membranes, and thus a quantitative simulation of diffusion in complex spatial locales is obtained without the use of voxels. MCell can produce two types of output are visualization output and reaction data output. Visualization output contains the specification of geometric meshes and the location and orientation of surface and volume molecules. Can be visualized using Cell Blender. Reaction data output contains time series of volume molecules counts in specified regions of the model, surface molecule counts on specified regions of the model, reaction counts, and hits or crossings of surface regions by volume molecules.
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Workshop on Biophysics Development of Yarn Based on Nanocellulose Composite Ahmad Kusumaatmaja Dept. of Physics, Faculty of Mathematics and Natural Sciences, Universitas Gadjah Mada
The abundance of cellulose in nature was a potential challenge to increase the added value of cellulose. Indonesia produced large palm oil, which resulted in a massive waste of oil palm empty fruit bunches had the advantage to utilize the cellulose. Nanocellulose is a natural polymer that potential for biomaterial application since its biocompatibility. However, the use of nanocellulose for medical applications is still limited, especially for suture. We reported the development of nanocellulose as yarn by wet electrospinning and cellulose fiber coated nanocellulose. For wet electrospinning, polyacrylonitrile was mixed with nanocellulose and then fed in electrospinning machine. The suture candidate was obtained from the collector and analyzed by scanning electron microscopy (SEM). Cellulose fiber coated nanocellulose was obtained by soaking the cellulose fiber in nanocellulose solution for specific hours. The resulted cellulose fiber coated nanocellulose was characterized by SEM, universal testing machine (UTM) for tensile strength and spectroscopy analysis. The presence of nanocellulose in the yarn was confirmed by SEM dan FTIR spectroscopy. The presence of nanocellulose also increased the yarn strength characteristic. The results also show that the yarn could be produced in those two methods and potentially to be used as a suture in medical application.
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Section III: ORAL PRESENTATION ORAL PRESENTASI - RADIOTHERPY
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Feasibility of Detecting Gold- and Bismuth-Originated Physical Dose Enhancement using GAFCHROMIC™ EBT3 Films in Proton Therapy Nashrulhaq Tagiling1,*, Raizulnasuha Ab Rashid1, Safri Zainal Abidin1, Khairunisak Abdul Razak2, Moshi Geso3, Takahiro Tominaga4, Ryohei Sasaki5, Hiroaki Akasaka5, Katahira Kie6, and Wan Nordiana Rahman1,* 1School of Health Sciences, Universiti Sains Malaysia, 16150, Kelantan, Malaysia of Materials and Mineral Resources Engineering, Universiti Sains Malaysia, 14300, Penang, Malaysia 3School of Health and Biomedical Sciences, RMIT University, 3083, Victoria, Australia 4Faculty of Health Sciences, Hiroshima International University, 739-2695, Hiroshima, Japan 5Division of Radiation Oncology, Kobe University Graduate School of Medicine, 650-0017, Kobe, Japan 6Hyogo Ion Beam Medical Centre, 679-5165, Hyogo, Japan * Email: [email protected], [email protected]
2School
ABSTRACT Interests in the combination of nanoparticles i.e. gold (AuNPs) or bismuth (BiNPs) with proton radiation has increased in recent years due to the promising therapeutic advantages in enhancing tumour cell death. While particle-induced emissions (PIE), secondary electrons and oxidative stress had been proposed as one of the many underlying mechanisms in NP-mediated proton dose enhancement, only a few had been motivated to estimate the contribution of each mechanism. Therefore, this work aims to look into the feasibility of using radiochromic films (RCFs) to measure the physical aspect of dose enhancement (PIE, secondary electrons) under proton beam irradiation. 0.5 mg of petroleum jelly capped with either AuNPs or BiNPs of the same concentration (10 mM) were loaded into 1.5 cm x 1.5 cm clear zipper bags packed with GAFCHROMIC™ EBT3 RCFs. The samples were exposed to a dose of 4.0 Gy at the centre of modulation of an 11.0 cm spread-out Bragg peak (SOBP) 150 MeV proton therapy system. Scanning was then conducted using an EPSON® Expression® 10000XL scanner in Red-channel. Two definitions of dose enhancement factor (DEF; ratio of optical density and ratio of dose) were introduced to analyse the data. Measurements for both NPs showed no significant physical DEFs beyond the dosimetry uncertainty of 1.48 %. Results from the two DEF definitions were also found to be statistically indifferent (P > 0.05). A conclusion had been drawn whereby the physical DEF accounts to a small fraction inside the overall DEF seen in proton-NPs radiobiological studies. Further in silico ventures are required to quantify physical proton radiosensitisation on a micro level. Keywords: Dosimetry, Radiochromic Films, Radiotherapy, Proton, Nanoparticles. REFERENCES 1. T. Guo, X-Ray Nanochemistry – Concepts and Development, Switzerland: Springer Nature, 2018, pp. 23-116
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Microstructure and Dose-Response Characterisation of Delaminated Films Dosimeter under 12 MeV Electron Beam Nashrulhaq Tagiling , Raizulnasuha Ab Rashid , Muhammad Afiq Khairil 1,*
1
Anuar1, Norhayati Dollah2, and Wan Nordiana Rahman1,* 1School
of Health Sciences, Universiti Sains Malaysia, 16150, Kelantan, Malaysia USM, Universiti Sains Malaysia, 16150, Kelantan, Malaysia * Email: [email protected]; [email protected]
2Hospital
ABSTRACT Delaminated GAFCHROMIC™ EBT3 radiochromic films (RCFs) are specialised dosimeters that are gaining attraction due to its many advantages. However, they are not available commercially and expensive compared to the regular EBT3 RCFs. The purpose of this study is to introduce a method to fabricate the delaminated EBT3 RCFs, microscopically examine the uncovered active layer compound (LiPCDA) and to evaluate the dose-response of the fabricated RCFs in electron beam radiotherapy. The delaminated EBT3 RCFs were first fabricated by carefully removing one of the two 125 μm polyester substrates using a precision forceps. Next, the films were irradiated using a 12 MeV electron beam at the measurement depth of 3.1 cm inside solid water slabs. Microstructure analysis was conducted by sputter coating non-irradiated and irradiated RCFs with a ~6 nm gold layer. Scanning electron microscope (SEM) was then used to look into the effects of radiation polymerisation onto the LiPCDA crystals at a magnification level of 3000x. To characterise the dose-response, the delaminated EBT3 RCFs’ optical density in Red-channel were analysed across a dose range of up to 500 cGy. The resulting dose-response curve was then compared with the regular EBT3 RCFs for performance evaluation. Results from the SEM images revealed that the irradiated active layer possesses a higher density of longer LiPCDA crystals (mode: 7.05 μm) compared to the non-irradiated active layer (mode: 5.63 μm). The delaminated EBT3 RCFs, nonetheless, was found to produce a net total uncertainty of 6.13 %, which is above its regular counterpart and also the radiotherapy’s tolerance level. In sum, this study had successfully demonstrated the effects of radiation polymerisation on the active layer. Anyhow, the delamination process had introduced a significant amount of uncertainty towards the doseresponse. More efforts into new delamination techniques are required to improve its usability in radiotherapy dosimetry. Keywords: Dosimetry, Radiochromic Films, Radiotherapy, Electron, Microstructure
REFERENCES 1. I. J. Das, Radiochromic Film Role and Applications in Radiation Dosimetry, Boca Raton, Florida: CRC Press, 2018, pp. 18.
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Reveal of Uncertainties of Soft-Tissue-based Patient Registration Due to Inter- and Intra-observer Variability in IGRT Era for Prostate Cancer Radiation Therapy Taka-aki Hirose *, Hidetaka Arimura2, Junichi Fukunaga , and Saiji Ohga3 1
1
1 Division
of Radiology, Department of Medical Technology, Kyushu University Hospital (3-1-1, Maidashi, Higashi-ku, Fukuoka, Japan) 2 Department of Health Sciences, Faculty of Medical Sciences, Kyushu University (3-1-1, Maidashi, Higashi-ku, Fukuoka, Japan) 3 Department of Radiology, National Hospital Organization Kyushu Medical Center (1-8-1, Jigyouhama, Chuo-ku, Fukuoka, Japan) * Email: [email protected]
ABSTRACT There remain the uncertainties in a soft-tissue-based patient registration even using a cone-beam computed tomography (CBCT) without fiducial markers due to inter- and intra-observer variability. We have revealed the uncertainties of the soft-tissue-based registration due to the variability against contour-based patient registration on CBCT images in prostate cancer image-guided radiation therapy (IGRT). [Methods] Ten patients (78 fractions), who underwent IGRT for prostate cancer, were selected. Five radiation therapists performed retrospectively soft-tissue-based registration between planning CT and pre-treatment CBCT images with respect to the prostate center after an automatic bone-based registration. The inter-observer variations of the soft-tissue-based registration were evaluated from the residual differences to the contourbased registration, which was performed based on the centroid of prostate contour delineated by a radiation oncologist. Then, each observer repeated the process three months later to evaluate intra-observer variations. The intra-observer variations were obtained from the difference between couch shifts of two soft-tissue-based registrations performed by a same observer for each fraction. Finally, systematic and random errors of the inter- and intra-observer variations caused by the five observers were estimated in anterior-posterior (AP), superior-inferior (SI), and left-right (LR) directions. [Results] The systematic interobserver variations in AP, SI, and LR directions were 0.7, 1.0, and 0.5 mm, respectively. The random interobserver variations in the three directions were 1.1, 1.4, and 0.6 mm, respectively. The systematic and random errors of intra-observer variations were less than 0.2 mm in all directions. [Discussion] The interobserver variations were larger than the intra-observer variations in this study. A previous study also reported that the inter-observer variations of prostate contour shifts ranged from 0.6 mm to 2.5 mm, while the intra-observer variations were less than 1 mm. For soft-tissue-based registration using the CBCT images, these uncertainties should be considered as CTV-to-PTV margins in the treatment planning of the IGRT era. Keywords: IGRT, Soft-tissue-based registration, CBCT, prostate cancer
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Prediction of Five-year Survival Probabilities of Head-and-neck Cancer Patients Based on Radiomic Signatures Selected by Coxnet Le Cuong Quoc1, Hidetaka Arimua2,*, Masahiro Yamada1, Hidemi Kamezawa3 1Department
of Health Sciences, Graduate School of Medical Sciences, Kyushu University, Japan 2Department of Health Sciences, Faculty of Medical Sciences, Kyushu University, Japan 3Department of Radiological Technology, Teikyo University, Japan * Email: [email protected]
ABSTRACT Five-year survival probability may affect the choice of treatment policies for head-and-neck (H&N) cancer patients. Our study aimed to investigate an automated approach for prediction of 5-year survival probabilities of H&N cancer patients using support vector machine (SVM). Computed tomography (CT) images of H&N squamous cell carcinoma [1] of 126 patients were selected from The Cancer Imaging Archive database [2] for this study. Engineered features representing tumor heterogeneity of cancer patients were extracted from gray-level histogram and texture matrices [3, 4] within gross tumor volume regions on CT images. All cancer patients were then divided into training and validation cohorts for making and evaluating a prediction model, respectively. Radiomic signatures, i.e., sets of significant features, were constructed using a Coxnet algorithm in the training cohort. The signatures were fed into the SVM with a polynomial kernel function for estimation of the 5-year survival probabilities. Other parameters of the polynomial SVM were optimized based on a leave-one-out test with the actual survival time. In the training cohort, the polynomial SVM learned with radiomic signatures achieved an area under the curve (AUC) of 0.7916 for stratification of patients based on 5-year survival. For a completely independent validation, the SVM model constructed in the training cohort were evaluated in the validation cohort for estimating the 5year survival probabilities. The performance of the SVM model with polynomial kernel achieved an AUC of 0.7363 in the validation cohort. The radiomics-based SVM could be feasible to estimate the 5-year survival probabilities of H&N cancer patients. Keywords: Head-and-neck cancer, Five-year survival probability, Coxnet, Support vector machine.
REFERENCES 1. Grossberg A, Mohamed A, Elhalawani H, et al., Imaging and Clinical Data Archive for Head and Neck Squamous Cell Carcinoma Patients with Radiotherapy, Scientific Data 5, Article number: 180173 (2018). 2. https://www.cancerimagingarchive.net/ 3. Haralick RM, Shanmugam K, Dinstein I, Textural features for image classification, IEEE Trans Syst Man Cybern 3, pp. 610-621 (1973). 4. Galloway MM, Texture analysis using gray level run lengths, Comput Graph Image Process 4, pp. 172-179 (1975).
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Comparison of Automated Atlas-Based Segmentation Software for Nasopharyngeal Carcinoma Radiotherapy K.Chhoeurt1,*, W.L.Jong2 and N.M.Ung2 National Cancer Centre, Calmette Hospital, Phnom Penh, Cambodia Clinical Oncology Unit, University Malaya Medical Centre, Kuala Lumpur, Malaysia * Email: [email protected] 1
2
ABSTRACT High accuracy in segmentation of target volume and organs at risk (OARs) is crucial for treatment planning especially in precision radiotherapy such as intensity modulation radiotherapy (IMRT) and image guide radiotherapy (IGRT) (Raudaschl et al.,2017; Delpon et al.,2016). It is challenging and time-consuming for oncologists to perform manual segmentation. Over the years, due to the advancement in computing, the automated atlas-based segmentation software has been widely introduced and available in the market. The purpose of this study is to compare the contours generated by four different commercial software namely Eclipse (Smart segmentation) from Varian, ABAS from Elekta, MIM Maestro, and Raystation from ReySearch for radiotherapy of nasopharyngeal carcinoma (NPC). The contours generated by software were benchmarked against contours generated by a radiation oncologist. Five NPC patients planned for IMRT from one oncologist were used to study. The study utilized the atlas database from the vendors’ expert library as well as new atlas database created from treated patient data in our institution. The structures of interest are the brainstem, eyes, larynx, spinal cord, mandible, parotid, cochlea and oral cavity. The comparison was evaluated quantitatively using (i) volume ratio (R), (ii) Dice Similarity coefficient (D) and (iii) Hausdorff distance (HD). The results showed some discrepancies on contours for various structures generated using different software. Atlas-based segmentation software has been shown to provide good starting point for delineation of structures, contributing to treatment planning workflow which is more efficient and time saving. Keywords: Automated atlas based-segmentation, intensity modulation radiotherapy (IMRT) image guided radiotherapy (IGRT), nasopharyngeal carcinoma (NPC).
REFERENCES 1. Raudaschl, P. F., Zaffino, P., Sharp, G. C., Spadea, M. F., Chen, A., Dawant, B. M., ... & Jung, F. (2017). Evaluation of segmentation methods on head and neck CT: Auto‐segmentation challenge 2015. Medical physics, 44(5), 2020-2036. 2. Delpon, G., Escande, A., Ruef, T., Darréon, J., Fontaine, J., Noblet, C., ... & Pasquier, D. (2016). Comparison of automated atlas-based segmentation software for postoperative prostate cancer radiotherapy. Frontiers in oncology, 6, 178.
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
The Accuracy of Modified Clarkson Integration (MCI) Algorithm for 3D Dose Reconstruction Evaluation Based on Log Files A D Handika1, S Mubarok2, W E Wibowo3, S A Pawiro1,* 1Department
of Physics, Faculty of Mathematics and Natural Sciences, University of Indonesia, Depok, 16424, West Java, Indonesia 2Department of Radiology, Fatmawati Hospital, South Jakarta, 12430, DKI Jakarta, Indonesia 3Department of Radiotherapy, Dr. Cipto Mangunkusumo National General Hospital, Central Jakarta, 10430, DKI Jakarta, Indonesia * Email: [email protected]
ABSTRACT Many researchers have investigated the linac log file for Intensity-Modulated Radiation Therapy (IMRT) and Volumetric Modulated Arc Therapy (VMAT) Quality Assurance (QA). In comparison between the conventional QA based on measurements, QA using log files offers various advantages including spatial sampling and higher temporal resolution. It does mean not require tools and phantoms in its measurements, but the QA based log file can be automatically generated and provide information for patient fractional delivery. The aim of this study was to develop and reconstruct 3D dose distribution for IMRT patientspecific QA based on linac log file using Modified Clarkson Integration (MCI) method. Linac log file from Varian Unique was extracted and calculated to 3D dose distribution using MATLAB version 2016a. Then, dose distribution from the log file was compared with DICOM RT Dose from Eclipse Treatment Planning System (TPS). Dose calculations using the MCI method for simple open fields of various variations (techniques, field size, and the depth) had discrepancy less than ±2% at isocenter. On the other hand, the calculation of gamma index evaluation with various criteria Dose Difference (DD) and Distance to Agreement (DTA) of 3%/3 mm, the passing rate is above 95%, while the criteria for 2%/2 mm and 1%/1 mm above 90%. This result showed that MCI method and the log file can be used for dose calculation and alternative IMRT patient-specific QA. Keywords: calculation, discrepancy, gamma index, QA.
REFERENCES 1. S. Liu, T. R. Mazur, H. Li, A. Curcuru, O. L. Green, B. Sun, S. Mutic, and D. Yang, App. Clin. Med. Phys. 18, 128-138 (2017). 2. J. H. Kung, G. T. Y. Chen, and F. K. Kuchnir, Med. Phys. 27, 2226-2230 (2000) 3. M. Pasler, V. Hernandez, N. Jornet, and C. H. Clark, Physics and Imaging in Radiation Oncology 5, 76-84 (2018) 4. N. Childress, Q. Chen, and Y. Rong, App. Clin. Med. Phys. 16, 4-7 (2015) 5. M. Saito, N Kadoya, K. Sato, K. Ito, S. Dobashi, K. Takeda, H. Onishi, and K. Jingu, App. Clin. Med. Phys. 18, 1-9 (2017) 6. D. L. Defoor, L. A. Vazquez-Quino, P. Mavroidis, N. Papanikolaou, and S. Stathakis, App. Clin. Med. Phys. 16, 206-215 (2015).
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Computer-Aided Diagnosis (CAD) to Detect Brain Abnormality from PET Images Using Artificial Neural Network (ANN) Y. Kusumawardani1, Ratianto2, P. Prajitno1, and D. S. Soejoko1,* 1Department
of Physics, Faculty of Mathematics and Natural Sciences, University of Indonesia, Depok, 16424, West Java, Indonesia 2Department of Nuclear Medicine, MRCCC Siloam Hospital, South Jakarta, 12930, DKI Jakarta, Indonesia * Email: [email protected]
ABSTRACT Positron Emission Tomography (PET) is well known as a molecular imaging modality that provides functional organ information. This information supports the results of anatomical imaging from other modalities such as Computed Tomography (CT) and Magnetic Resonance Imaging (MRI). This superiority is due to the ability of PET to detect of small amount uptake from FDG which provide for information about abnormalities of organs, especially in the brain. Therefore, PET imaging is powerful to diagnose the presence of abnormalities, staging cancer, and evaluating radiotherapy treatment results. In brain PET imaging sometimes, small uptake is not easily visual recognized, hence an additional supporting method for its detection is needed. In this study, Computer-Aided Diagnosis (CAD) of brain abnormalities from PET images using segmentation and classification methods based on a feature in the form of Gray Level Co-Occurrence Matrix (GLCM) as a dataset of Artificial Neural Network (ANN). A total number of samples were 365 images with 143 abnormal and 222 normal images were used as training and testing data. The result based on Receiver Operating Characteristic (ROC) illustrated that the training error was 6.6% and the test error was 3.6%. These results mean that this developed CAD system can recognize normal and abnormal brain images. Keywords: Abnormalities, Brain, CAD, and PET
REFERENCES 1. M. Angulakshmi and G. G. Lakshmi Priya, International Journal of Imaging Systems and Technology (2017), 27(1) 66-77. 2. G. Castellano, L. Bonilha, L. M. Li, and F. Cendes, Clinical Radiology (2004) 59, 1061-1069. 3. Z. CÖmer and A. F. Kocamaz, Internasional Artificial Intelligence and Data Processing Symposium (17-18 September 2016) 4. K. Doi, Comput Med Imaging Graph, 2007; 31(4-5): 198-211. 5. M. J. Strong, et al., Journal of Brain Tumors and Neurooncology (2015) 1:1.
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Computer-Aided Diagnosis (CAD) to Detect Abnormalities in Lung Pediatric Radiography using Particle Swarm Optimization Method M.L.E. Yuliansyah1* , P.Prajitno1, D.S. Soejoko1 1Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok, Jawa Barat, 16424, Indonesia * Email: [email protected]
ABSTRACT More than 10 million people worldwide die annually from chest diseases. Based on the survey that has been done, the mortality rates for chest diseases in 1990 are 2.2 million because of chronic obstructive pulmonary disease and 2 million because of tuberculosis [1]. The abnormality of organs in the chest cavity, one of which these is a lung organ, requires very accurate analysis and interpretation. Nodules that are expected to be obviously visible, sometimes covered by another complex lung tissue which is normal tissues. Therefore an innovation is needed in analyzing and classifying normal tissue and the nodule [2,3]. The whole process is packaged in the form of Computer-Aided Diagnosis that is a computer-based digital image processing which consists of image filtering and image segmentation process in order to achieve successful classification in detecting the abnormality in lung image. In this tool, Particle Swarm Optimization (PSO)based segmentation method is combined with Fuzzy C-Means (FCM) clustering method and Wiener filter to refine the lung region and search abnormalities, especially for pneumonia and tuberculosis, based on the value of the image pixel. The performance evaluation of this CAD was done by calculating the Receiver Operating Characteristics (ROC) using 136 images and compared with the reference from doctor evaluation. The overall error of this method is 11.43% or has an accuracy value of 88.57%, while its sensitivity is 90.00%, specificity is 85.00%, and precision is 93.75%. This means that this method have a good success rate in in detecting the abnormal lung image. Keywords: CAD, particle swarm optimization, image segmentation, lung image.
REFERENCES 1. Murray CJ, Lopez AD, Lancet, 349, (1997) 1269–76 2. Sluimer, A. Schilham, M. Prokop, and B. Van Ginneken. (2006) “Computer analysis of computed tomography scans of the lung: A survey,” IEEE Trans. Med. Imaging, vol. 25, no. 4, pp. 385–405, Apr. 3. T. Messay, R. C. Hardie, and S. K. Rogers. (2010) “A new computationally efficient CAD system for pulmonary nodule detection in CT imagery,” Med. Image Anal., vol. 14, no. 3, pp. 390–406, Jun.
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Feasibility of Megavoltage CT in High Dose Adaptive Planning for Hepatocellular Carcinoma Cancer of Helical Tomotherapy and Linac Treatment Plans Ahmad Syafi’i1, Nuruddin Nasution2, Wahyu E. Wibowo2, Supriyanto A.Pawiro1* 1Departement
of Physics, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, West Java of Radiotherapy, Dr. CiptoMangunkusumo National General Hospital, Central Jakarta * Email: [email protected]
2Departement
ABSTRACT The acquisition of Megavoltage Computed Tomography (MVCT) image on Helical Tomotherapy (HT) is a mandatory procedure for verifying patient position before the irradiation. Various effects in tumor doses, the organ at risk (OAR) dose and patient total doses from the shifting position on the setup patient verification have been studied. The prior study indicates that the stability of MVCT images is relatively constant, so it is possible to register with Kilovoltage CT (KVCT) image. Adaptive planning using MVCT registered with KVCT in a conventional treatment dose per fraction represents for better planning, reduced OAR dose, but for some cases, adaptive planning does not show the benefit of the procedure. This work evaluated the use of MVCT in high dose treatment (hypofractination) on HT and Linac. Nine patients of Stereotactic Body Radiation Therapy (SBRT) technique for liver cancer cases or hepatocellular carcinoma (HCC) from Cipto Mangunkusumo Hospital were used with 3-8 Gy per fraction in 4-10 fractions previously for HT. In some cases, the treatment is exported from HT to the Linac due to machine maintenance or failure. The comparison between adaptive planning based on MVCT in HT and Linac to KVCT has been investigated due to the high dose and the difference between two modalities of the machine, so that. Planning analysis from Tomo Plan Station (HT) and Pinnacle (Linac) using MVCT dan KVCT shows that Conformity Index (CI) varies from 0.8-1 (mean 0.98), Homogenity Index (HI) ranges from 0.02 to 0.5 (mean 0.16) and Gradient-Index values 2.8-6. The OAR’s planning from both modalities has met the RTOG criteria for SBRT. These results suggest that besides for position verification, MVCT can be used as alternative modalities for planning in HT and Linac. The verification between the plan and the treatment using gamma index criteria need to be examined later. Keywords: MVCT, Adaptive Planning, High Dose, Helical Tomotherapy, Plan Analysis
REFERENCES 1. J. Zhu et al, Effect of Megavoltage Computed Tomographic Scan Metodology on Set Up Verification and Adaptive Dose Calculation in Helical Tomotherapy, Radiation Oncology, 2018, pp 2-11. 2. P. Yadav et al, The Effect and Stability of MVCT Images on Adaptive Tomotherapy, Journal of Applied Clinical Medical Physics, 2010, pp. 4-14. 3. P. Yadav et al, Adaptive Planning using Megavoltage Fan-Beam CT For Radiation Therapy with Testicular Shielding, Medical Dosimetry, 2012, pp. 157-162.. 4. M. Branchini et al, Skin Dose Calculation During Radiotherapy of Head and Neck Cancer Using Deformable Image Registration of Planning And Mega-Voltage Computed Tomography Scans, Physics and Imaging in Radiation Oncology, 2018, pp. 44-50 5. D.J. Noble et al, Anatomical Change During Radiotherapy for Head and Neck Cancer, and Its Effect on Delivered Dose to The Spinal Cord, 2018, Radiotherapy and Oncology.
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Dosimetric Comparison between Single and Double Isocenters VMAT for Stereotactic Radiation Therapy with Multiple Targets Wai Lwin Lwin Kyaw*, Sivalee Suriyapee, Chotika Jumpangern, Taweap Sanghangthum Medical Physic School, Department of Radiology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand * Email: [email protected]
ABSTRACT The purpose of this study was to evaluate the dosimetric effects between single isocenter (SI) and double isocenters (DI) VMAT SRT of multiple brain metastases. Eighteen VMAT SRT plans with varying lesions size, number and distance were simulated on patient CT image using Eclipse treatment planning system version 11.0.31. The plan consists of 3 techniques in: 2 coplanar arcs SI, 1 coplanar combine with 2 non-coplanar arcs SI and 2 non-coplanar and 1 coplanar arc DI. The VMAT plans were generated with 21Gy prescription dose to all lesions in 3 fractions. The plans were evaluated in terms of Conformity index (CIRTOG), Homogeneity index (HIRTOG), and Gradient index (GIPaddick) for PTV and V12Gy and V6Gy for normal brain. The same dose constraints were used to optimize for all cases. On the average result from 3 techniques, 2 arcs and 3 arcs SI plans were better in CI (1.09 ± 0.13, 1.12 ± 0.14) than DI (1.18 ± 0.08) and 3 arcs SI and DI were improvement in GI (9.84 ± 2.7, 9.88 ± 2.84) than the 2 arcs SI (11.68 ± 3.07) while HI values was comparable for all techniques. For normal brain, V12Gy for 2 arcs and 3arcs SI plans were comparable with DI and the volumes of normal brain receiving 6 Gy in 3 arcs SI and DI (68.80 ± 37.96 cm3, 69.95 ± 36.75 cm3) were better than 2 arcs SI (81.2 ± 51.47 cm3). Moreover, the number of arcs, monitoring units and also treatment time were increased by nearly 2-fold and inconvenience in practice in DI. In conclusion, 3 arcs non-coplanar SI VMAT technique presents the best in dosimetric evaluation in 2-5 lesions metastases SRT.
Keywords: SRT, SI, DI and VMAT.
REFERENCES 1. G.M. Clark, R.A. Popple, and P.E. Young. “Feasibility of single-isocenter volumetric modulated arc radiosurgery for treatment of multiple brain metastases”, Int J Radiation Oncol Biol Phys, 2010, pp. 296-302. 2. J. Morrison, R. Hood, F.F. Yin, J. Salama, J. Kirkpatrick, and J. Adamson. “Is a single isocenter sufficient for volumetric modulated arc therapy radiosurgery when multiple intracranial metastases are spatially dispersed?” Med Dosim, 2016, pp. 285-289. 3. A.L. Salkeld, K. Unicomb, A.J. Hayden, K. Van Tilburg, and S. Yau. “Dosimetric comparison of volumetric modulated arc therapy and linear accelerator-based radiosurgery for the treatment of one to four brain metastases”, J Med Imaging Radiation Oncol, 2014, pp. 722-8.l
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Development of a Fluence Generating Program for Patient Specific QA and Calibration of Elekta EPID Chuey Fen Yeap1, Wei Loong Jong2,*, and Ngie Min Ung 1Department
of Biomedical Imaging, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia; Oncology Unit, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia * [email protected]
2Clinical
ABSTRACT Patient specific quality assurance (QA) is an essential part of intensity modulated radiotherapy (IMRT) and volumetric arc therapy(VMAT) treatment. The purpose of this study is to develop a cost-effective approach to patient specific QA through development of a fluence generating program and utilization of an electronic portal imaging device (EPID), which is incorporated with every LINAC for setup verification. Five simple and one patient VMAT plans were created using Monaco treatment planning system. A fluence generating program was written using MATLAB. Fluence maps were then generated from the aforementioned plans using this in-house developed program. The accuracy of program was evaluated by performing gamma analysis between the generated and measured fluence from calibrated Elekta EPID and 2D array (MatriXX Evolution). The EPID was also investigated on dependency of dose rate, uniformity of detector sensitivity and output factor. Detector response of EPID and 2D array were found to be linearly proportional to dose from 1-1000 MU. Signal dependency on dose rate is less than 0.5% while mean uniformity ratio is 1.07±0.03%. After applying uniformity correction and output factor on EPID fluence, the measured fluence from EPID and 2D array were in good agreement with the generated fluence . A fluence generating program was successfully developed, providing a simple and cost-effective mean patient specific QA for IMRT/VMAT delivery.
Keywords: Patient specific QA, EPID calibration, fluence generating program, gamma analysis.
REFERENCES 1. Mukhtar Alshanqity, & Andrew Nisbet. (2016). Dosimetric performance of a-si electronic portal imaging devices. International Journal of Medical Physics, Clinical Engineering and Radiation Oncology, 5(02), 162. 2. Ann Van Esch, Tom Depuydt, & Pierre Huyskens Dominique. (2004). The use of an aSi-based EPID for routine absolute dosimetric pre-treatment verification of dynamic IMRT fields. 71(2), 223-234. 3. Prabakar Sukumar, Sriram Padmanaban, Prakash Jeevanandam, S. A. Syam Kumar, & Vivekanandan Nagarajan. (2011). A study on dosimetric properties of electronic portal imaging device and its use as a quality assurance tool in Volumetric Modulated Arc Therapy. Reports of Practical Oncology & Radiotherapy, 16(6), 248-255. 4. W. D. Renner, K. Norton, & T. Holmes. (2005). A method for deconvolution of integrated electronic portal images to obtain incident fluence for dose reconstruction. J Appl Clin Med Phys, 6(4), 22-39. 5. M. Hussein, E. J. Adams, T. J. Jordan, C. H. Clark, & A. Nisbet. (2013). A critical evaluation of the PTW 2DARRAY seven29 and OCTAVIUS II phantom for IMRT and VMAT verification. J Appl Clin Med Phys, 14(6), 4460.
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Leipzig Brachytherapy in HDR Brachytherapy : Dosimetry and Technical Consideration Anisza Okselia1*, Marhendra Satria Utama2, and Freddy Haryanto1 1Department
of Physics, Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology, Ganesha 10, Bandung 40132, West Java, Indonesia. 2Faculty of Medicine, University of Padjajaran, Bandung, West Java * Email: [email protected]
ABSTRACT Leipzig with high dose rate brachytherapy offer an alternative modality from electron therapy for the treatment of superficial skin cancer is effective to reduce the waiting list for patient treatment time frequently treated by external radiotherapy. The aim of this research is to find out the effective reference depth of Iridium – 192 source in Leipzig Brachytherapy to get the optimal and homogeneous dose. Treatment delivered by microSelectronHDR afterloader brachytherapy with Leipzig applicators using Iridium – 192 source. Planning using the 2D Brachytherapy Treatment Planning System was first carried out to plan radiation treatment by using a dose regimen of 2250 cGy in 5 fraction. Measurements have done in several condition, that are vertical and horizontal type applicator; with or without plastic cup; and several size of Leipzig applicator diameter. Reference depth to get 100% dose has varied in order to obtain homogeneity dose. It has proven that Leipzig applicator using protective cap and not using protective cap has different isodose curve. The result is that homogeneity of Leipzig applicator using protective cap has 90% coverage and 75% if not using protective cap with same size of cone. The radiation time for vertical type Leipzig applicator is 2 times faster than horizontal type of applicator. The dose is getting homogeny and optimal in 5 mm depth from the plastic cup. Distribution dose of Brachytherapy Iridium – 192 in Leipzig applicator affected by size, type, and shape of the applicator by itself, adjusted by the size and type of tumor. Small lesions of skin cancer with 5 mm depth can treated by Leipzig brachytherapy and have a good result thus effective in clinical practice.
Keywords: Leipzig Brachytherapy, Superficial Skin Cancer, High Dose Rate Brachytherapy, Dosimetry
REFERENCES 1. Albert M.Sabbas, Ph.D, HDR Brachytherapy with Surface Applicators:Technical Considerations and Dosimetry, Technology in Cancer Research and Treatment, ISSN 1533 – 0346, 2004. 2. S. Sarudis, "Dose Distribution Beneath The Leipzig Skin Applicator Set", M.Sc. Thesis, University of Stockholm, 2006. 3. J. Skowronek, Brachytherapy in a Treatment of Skin Cancer: An Overview, Review Paper, Postep Derm Alergol, 2015; XXXII (5), pp. 362 – 367. 4. J. Perez-Calatayud, D. Granero, B. Facundo, P. Vicente, C. Emilio, S. Angela, Vicente C. A Dosimetric Study Of Leipzig Applicators. Int. J. Radiation Oncology Biol, Phys., Vol. 62, No.2, pp.579 – 584, 2005. 5. Granero D, Candela – Juan C, Vijande J, Ballester F, Perez-Calatayud J, Jacob D, Mourtada F. Technical Note: Dosimetry of Leipzig and Valencia Applicators Without The Plastic Cup. Medical Physics, Vol. 43, No.5, pp. 2087 – 2090, 2016.
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Computer-Aided Diagnosis (CAD) for Detecting Abnormality on CT Liver Images W S Wahyuni1, P Prajitno1 and D S Soejoko1,* Departement of Physics, Faculty of Mathematics and Natural Science, Universitas Indonesia, Depok, 16424, Indonesia. * Email: [email protected]
1
ABSTRACT Liver abnormalities in CT image commonly have different shape, location and texture. The contrast between abnormalities and healthy liver often cannot be clearly seen, making it difficult to evaluate. Liver abnormalities include swelling, fibrosis, the presence of benign tumors or malignant tumors. Low contrast differences with width measurements in images are easily recognized as abnormalities, but for small masses and low contrast it is difficult to evaluate. In this study CAD was carried out with the aim to help evaluate liver abnormalities, especially small size abnormalities. The segmentation method based on active contour is the method was employed in this research. The data which used was secondary data resulting abdomen image from modalities of Computed Tomography Scanner (CT-Scan) of Cibinong Hospital, Bogor. The data collection techniques was used in this research were data abnormal liver image from patients liver cancer and normal liver image from patients other diseases according to the doctor's diagnosis.Meanwhile, the technique used to processing data was extraction feature process with analysis Gray-Level Co-occurrence Matrix (GLCM) texture and machine learning of Artificial Neural Network (ANN) for detection abnormality image. Results of this research stated that ANN can used for classify image to normal and abnormal group with training error of 10% and test error of 7.2%.
Keywords: Segmentation, Active Contour, GLCM, Classification, ANN.
REFERENCES 1. M Abdel-massieh.N.H., Hadhoud.M.M., and Moustafa.K.A.,(2010) “A fully automatic and efficient technique for liver segmentation from abdominal CT images,” in Proc. 7th Int. Conf. Inform. Syst. (INFOS),pp. 1–8. 2. Ben-Dan.I. and Shenhav.E.,(2008) “Liver Tumor segmentation in CT images using probabilistic methods,” in Proc. 11th Int. Conf. Med. Image Comput. Comput. Assisted Intervention, MICCAI’08,, New York, pp. 1–11. 3. Geleijns, J. “Computed Tomography.” Diagnostic Radiology Physics: A Handbook for Teachers ans Students. Ed. D.R. Dance, S. Christofides, A.D.A. Maidment, I.D. McLean & K.H. Ng. International Atomic Energy Agency Library. 2014. 257-290. 4. Gonzalez, R.C. and R.E. Woods. Digital Image Processing. India: Pearson Education, 2002. 5. Hassan Masoumi, Alireza Behrad, Mohammad Ali Pourmina, Alireza Roosta, “Automatic liver segmentation in MRI images using an iterative watershed algorithm and artificial neural network.” Elsevier 7 (2012): 429-437. 6. Hung, N.Q, M.S. Babel, S. Weesakul, and N.K. Tripathi. 2009. “An Artificial Neural Network Model for Rainfall Forecasting In Bangkok, Thailand”. Hydrol. Earth Syst. Sci., 13: 1413–1425. 7. R.S. Moni, S.S. Kumar dan J. Rajeesh, “Automatic Segmentation of Liver and Tumor for CAD of Liver,” Journal Of Advances In Information Technology, Vol. 2, No. 1, hal. 63-70, Februari 2011
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Monte Carlo Study of Nuclear Fragmentation in Water Irradiated with Protons and 12C Ions for Particle Therapy Applications Vernie C. Convicto1,2,3*, Dainna Recel S. Pamisa1,2, Abdurajan B. Lintasan1,2,4 and Catherine Therese J. Quiñones1,2 1 Mindanao Radiation Physics Center, Premier Research Institute of Science and Mathematics Mindanao State University – Iligan Institute of Technology, A. Bonifacio Avenue, 9200 Iligan City, Philippines 2Physics Department, Mindanao State University – Iligan Institute of Technology, A. Bonifacio Avenue, 9200 Iligan City, Philippines 3Physics Department, Mindanao State University-Marawi Campus, 9700 Marawi City, Philippines 4Mathematics and Sciences Department, Mindanao State University-Tawi-tawi, Sanga-sanga Campus, Bonggao, 7500 Tawi-tawi, Philippines * Email: [email protected]
ABSTRACT In this study, the nuclear fragmentation of the secondary particles produced when water is irradiated with heavy-ions such as protons and carbon were investigated. Proton beams with varying incident energies of 100 MeV, 130 MeV, 150 MeV and 160 MeV were used with corresponding carbon-12 ion beams of about 187.50 MeV/u, 241.67 MeV/u, 285.42 MeV/u and 308.33 MeV/u respectively. The chosen energy falls within an average human body which offers excellent conditions for tumor therapy, in particular for the treatment of deep-seated radio-resistant tumors. The kinetic energy distribution and energy deposition of primary and secondary particles were studied via Monte Carlo simulation with the aid of GATE v.8.0 via the Geant4 simulation toolkit version 10.3.2 with 1 x 106 incident beams. The physics list used was QGSP_BIC (Quark Gluon String Pre-compound Binary Cascade). When the primary carbon ion and proton beams interact with water, secondary light-charged particles and heavycharged particles with atomic number Z >2 are produced. In general, it was shown that the incident carbon ions are less scattered as they traverse matter compared to the incident protons. As a result, the energy deposition of incident carbon ions is well-defined and is better in terms of conformation. However, due to the huge amount of scattered secondary particles, the energy deposition using incident carbon ions exhibit fragment tail, i.e. dose tail in the depthdose profile. Therefore, in order to have an accurate dose calculations, nuclear fragmentation of secondary particles are to be properly taken into consideration for organs at risks may be located in this region.
Keywords: fragmentation, lateral profile, energy deposition, Bragg peak, Proton beams, Carbon-12 ions.
REFERENCES 1. J.-E. García-Ramos et al. (eds.), Basic Concepts in Nuclear Physics: Theory, Experiments and Applications, Springer Proceedings in Physics 182, Springer International Publishing Switzerland, p.55 (2016). 2. E. Haettner et al., Experimental study of nuclear fragmentation of 200 and 400 MeV/u 12C ions in water for applications in particle therapy. Phys. Med. Biol. 58(23), 8265–8279 (2013).
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Computer-Aided Detection of Mediastinal Lymph Nodes using Simple Architectural Convolutional Neural Network E. Kurniawan1, P. Prajitno , D. S. Soejoko 1,*
1Department
1
of Physics, Faculty of Mathematics and Natural Science, Universitas Indonesia, Depok, 16424, Indonesia. * Email: [email protected]
ABSTRACT Mediastinal lymph nodes detection is important in the staging of lung cancer. The detection of mediastinal lymph nodes is challenging due to the low contrast between the nodes and the surrounding tissues. Several computer-aided detection (CADe) methods to detect mediastinal lymph nodes automatically have been proposed to assist the radiologists. In this work, we proposed a simple architectural convolutional neural network (CNN) for automatic detection of mediastinal lymph nodes. We used a total of 388 mediastinal lymph nodes in CT images of 90 patients as the positive class samples for the training of the CNN. Data augmentation was implemented to the positive class samples in order to multiply the training data. The mean of the Hounsfield Unit (HU) and the geometric parameters of mediastinal lymph nodes were used to do the false positive reduction. We tested our pre-trained model to differentiate between positive and negative test samples with 252 samples in each class and 24 × 24 pixel per sample. The model achieved a promising result to be developed as a CADe system with 98,8% sensitivity and 92,4% specificity in differentiating between positive and negative test samples. In future works, we intend to develop a sliding window mechanism using the model in order to scan whole CT images of the test data. Finally, we will calculate the sensitivity and the false positive rate to evaluate the performance of the CADe system based on our model.
Keywords: mediastinal lymph nodes, convolutional neural networks, CT image, computer-aided detection, deep learning
REFERENCES 1. Shin, H., Roth, H. R., Gao, M., Lu, L., Xu, Z., Nogues, I., Yao, J., Mollura, D., and Summers, R. M., Deep Convolutional Neural Networks for Computer-Aided Detection : CNN Architectures , Dataset Characteristics and Transfer Learning, IEEE Transactions on Medical Imaging 35, 1285-1298 (2016). 2. Liu, J., Hoffman, J., Zhao, J., Yao, J., Lu, L., Kim, L., Turkbey, E. B., dan Summers, R. M., Mediastinal lymph Node Detection and Station Mapping on Chest CT Using Spatial Priors and Random Forest, Med. Phys. 43, 4362-4374 (2016).
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Monte Carlo Investigation Of The Depth-dose Profile Of Proton Beams And Carbon Ions In Water, Skeletal Muscle, Adipose Tissue, And Cortical Bone For Hadron Therapy Applications Dainna Recel S. Pamisa , Vernie C. Convicto , Abdurajan B. Lintasan and Catherine Therese J. Quiñones1,2 1,2,*
1,2,3
1,2,4
1Mindanao Radiation Physics Center, Premier Research Institute of Science and Mathematics, Mindanao State University – Iligan Institute of Technology, A. Bonifacio Avenue, 9200 Iligan City, Philippines 2Physics Department, Mindanao State University – Iligan Institute of Technology, A. Bonifacio Avenue, 9200 Iligan City, Philippines 3Physics Department, Mindanao State University-Marawi Campus, 9700 Marawi City, Philippines 4Mathematics and Sciences Department, Mindanao State University-Tawi-tawi, Sanga-sanga Campus, Bonggao, 7500 Tawi-tawi, Philippines * Email: [email protected]
ABSTRACT Protons and carbon ions offer advantage over the conventional radiotherapy modalities because of their depth-dose profile described by a Bragg peak which allows precise dose localization and higher relative biological effectiveness (RBE). This study aims to investigate the depth-dose profile of proton beams, determining the position of the Bragg peak (i.e. range) at different incident energies, and to determine the energies of corresponding carbon ions which can produce approximately the same Bragg peak as the chosen proton beam energies. Monte Carlo simulations are conducted using GEANT4 version 10.3.2 via GATE v.8.0. The virtual set-up is composed of a 20 cm x 20 cm x 20 cm target with material varied using water, skeletal muscle, adipose tissue, and cortical bone. The source was placed 11 cm away from the center of the target. The physics list QGSP_BIC (Quark Gluon String Pre-compound Binary Cascade) is utilized. The proton beam with one million primaries is set with varying energies of 75 MeV, 100 MeV, 130 MeV, 150 MeV, and 160 MeV. The ranges of the simulated proton beams are compared with the experimental values from the National Institute of Standard and Technology. The energy of carbon ions with approximately the same stopping range as the pre-chosen proton beam energies are determined. The depth-dose profile obtained using carbon ions show narrower Bragg peak suggesting better dose conformation, but the presence of dose tail suggests dose deposition due to secondary particles. The results show significant amount of secondary protons, alpha particles, and fragments of helium, boron, lithium, and beryllium. Investigation of the RBE of these secondary fragments is necessary to understand their underlying impact to the treatment. In general, it was found that the range of carbon ions and protons is dependent on the energy of the incident particle and on the target material.
Keywords: Hadron therapy, proton beam, carbon ions, Bragg peak, fragmentation
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Dose-volume Histograms Comparison From Two Different Beam Configurations In The Monte Carlo Simulation of 6MV Clinac2100 Using PRIMO Program Hermes Bacala1*, Agnette Peralta1, Salasa Nawang2 and Angelina Bacala2 1The
Graduate School, University of Santo Tomas, Manila, Philippines of Physics, MSU-Iligan Institute of Technology, Iligan City, Philippines * Email: [email protected]
2Department
ABSTRACT The Monte Carlo (MC) method is widely considered to provide the most accurate dose distribution in external beam radiotherapy. A self-contained, full MC linac simulator and dose calculator, PRIMO is a windows-based, freely-distributed software which allows the importation of external compliant phasespace files among its many capabilities. Using PRIMO, a Varian Clinac2100 is simulated at 6 MV nominal energy for 108 number of histories. The dose calculations are compared using two different initial electron beam configurations. The tuned-beam profile has initial electron beam energy of 6.26 MeV, 0.150 MeV full-width-half- maximum (FWHM), 0.150 cm focal spot FWHM and 2 beam divergence. The default configuration given in PRIMO has 5.40 MeV as initial electron beam energy and zero values for all the other beam parameters. A brain computerized tomography (CT) volume is imported into PRIMO and using its contouring tools, these structures are delineated: a hypothetical gross-tumor volume (GTV), the brain, the left- and right lens. The CT volume is irradiated with two parallel-opposed fields of size 10x10cm2 with the brain conformed using the 52-leaf MLC. The dose-volume histogram (DVH) of the GTV and the brain for the tuned-beam profile has a larger extent into the high dose region compared to the DVHs of the default beam configuration. The dose given to 95% of the volume (D95) and the percentage of the volume receiving a dose equal to 95% (V95) are also compared. The GTV for the default beam profile has D95 = 86.31% with V95 = 0.44%, while for the tuned-beam profile, D95 = 88.30% with V95 = 0.95%. For the brain, D95 = 2.55% with V95 = 1.13% for the default profile while the tuned beam profile gives D95 = 2.43% with V95 = 2.33%. For the left [right] lens, D95 = 0.15% [D95 = 0.11%] for the default profile and D95 = 0.16% [D95 = 0.081%] for the tuned beam profile. Both beam profiles give V95 = 0% for the left- and right-lens. Keywords: Monte Carlo dose calculation, PRIMO software, dose-volume histograms
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Quantitative Assessment For IMRT Plan Conformity: A Virtual Phantom Study Hwee Shin Soh1,2,*, Keith A Langmack3, Paul S Morgan1,3 and Alan C Perkins1,3 1Radiological
Sciences, School of Medicine, University of Nottingham, Nottingham, NG7 2UH, United Kingdom. Radiation Surveillance Division, Block E3, Parcel E, Federal Government Administrative Centre, 62590 Putrajaya, Malaysia. 3Medical Physics and Clinical Engineering, Nottingham University Hospitals NHS Trust, Nottingham, NG7 2UH, United Kingdom. * Email: [email protected]
2Medical
ABSTRACT Introduction: In IMRT treatment planning, there has been little interest in defining parameters to assess the quality of the treatment plan using quantitative metrics. This work was carried out for the first time to develop a series of virtual phantom to assess the IMRT planning conformity. Methods: A series of virtual phantoms were designed by using MATLAB® software (MathWorks, Natick, MA, United States), simulating a cylindrical-shaped planning target volume (PTV) surrounded by two cylindrical shaped organ-at-risk (OARs). The separation of PTV-OARs was designed to have variable distances. Three different IMRT techniques were investigated: step-and-shoot IMRT (SSIMRT), volumetric modulated arc therapy (VMAT) and helical tomotherapy (HT). The dosimetric results were analysed for PTV (D2% and D95%) and OARs (V40Gy and V65Gy). Later, both the metrics of conformity index (CI) and conformation number (CN) were used to examine and compare the conformity of the plans. Results: Both VMAT and HT showed good coverage of PTV with 95% of the PTV (D95%) receiving more than 90% of the prescribed dose. VMAT provided a significantly higher average D95% than HT for all the separation groups. However, SSIMRT plans failed to meet the planning objectives of D95% when PTV and OARs are adjacent to each other. The conformity analysis showed that SSIMRT has lower average CI values of 0.705 ± 0.109. Additionally, HT had slightly better plan conformity than VMAT with the consistency of average CI value (range 1.003 - 1.028) regardless the PTV-OARs separation. Similar to CI, the SSIMRT plans reveal a lower average CN values of 0.628 ± 0.058 when PTV and OARs are adjacent to each other. HT has the consistency of average CN value (ranged 0.715 - 0.758) regardless the PTVOARs separation. Conclusion: This study has demonstrated the conformity assessments on all the IMRT plans generated using the virtual phantoms. The results of these studies have shown for the first time, the feasibility of using the measure of CI and CN on virtual phantoms for assessing plan conformity.
Keywords: IMRT plan quality, quantitative assessment, virtual phantom.
REFERENCES 1. International Commission on Radiation Units and Measurement. Report 83: Prescribing, Recording, and Reporting Photon-Beam Intensity-Modulated Radiation Therapy (IMRT). J ICRU, 10(1): NP.3-NP (2010). 2. A. van't Riet, A. C. Mak, M. A. Moerland, L. H. Elders, and W. van der Zee. A conformation number to quantify the degree of conformality in brachytherapy and external beam irradiation: application to the prostate. Int J Radiat Oncol Biol Phys, 37(3): 731-6 (1997). 3. I. Paddick. A simple scoring ratio to index the conformity of radiosurgical treatment plans. J Neurosurg, 93 Suppl 3: 219-22 (2000).
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Stopping Power Ratio Databases For Proton Therapy Dose Calculation N Pischom1,2*, S Asavaphatiboon1, P Tangboonduangjit1 and T Liamsuwan3,4 1 The
School of Medical Physics, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand 2 Division of Radiotherapy, Department of Radiology, Surin Hospital, Surin, Thailand 3 Faculty of Medicine and Public Health, HRH Princess Chulabhorn College of Medical Science (PCCMS), Chulabhorn Royal Academy, Bangkok, Thailand 4 Nuclear Research and Development Division, Thailand Institute of Nuclear Technology (Public Organization), Nakhon Nayok, Thailand * Email: [email protected]
ABSTRACT In modern therapy, ion beams are increasingly used for cancer treatment. Protons are light ions that have Bragg peak characteristic in the depth dose distribution that is optimal for minimizing dose to surrounding normal tissues. In proton therapy treatment planning, the stopping power ratio (SPR) of medium to water is used for calculating the dose for the patient. The SPR is related to the Computed Tomography (CT) number. The conversion from CT number to SPR is used to find water equivalent pathlengths (WEPL) of tissue voxels, which are sequentially applied to select the initial proton energy. Recently, a MATLAB-based proton therapy treatment planning system called PSPLAN based on the pencil beam scanning technique and pencil beam algorithm has been developed. PSPLAN requires CT images and calculates proton SPR based on tissue compositions and mass stopping powers extracted from the PSTAR database. PSTAR provides mass stopping powers of some elements and compounds. However, mass stopping powers of elements such as Calcium, Phosphorus, Sulfur do not exist. Therefore, these elements have been excluded from the stopping powers of tissues. The previous study has shown that excluding these elements from the tissue compositions resulted in the passing rates of less than 90% for the gamma index 3%/3mm when comparing pencil beam dose distributions calculated by PSPLAN with Monte Carlo simulation. To improve the accuracy of dose distribution calculation of PSPLAN, this work will study the effect of CT number to stopping power ratio conversion models, which are based on well-accepted mass stopping power databases and include all relevant elements in the tissue compositions. The results will help to quantify dose uncertainty and range uncertainty associated with SPR conversion.
Keywords: proton therapy, stopping power ratio, CT number, treatment planning system, Monte Carlo simulation
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Thermoluminescence Response of Germanium Doped Silica Glass Fibers Due to Kilovoltage Energy X-Ray Irradiation Amirruddin Abd Rahman1, Alisha Gilbert Sulin1, Mustafidzul Mustapha1, Hafiz M Zin2, Ahmad Taufek Abdul Rahman1, 3, * 1Faculty
of Applied Science, Universiti Teknologi MARA, 40450 Shah Alam,Selangor, Malaysia; Medical and Dental Institute, Universiti Sains Malaysia, 13200 Bertam, Pulau Pinang, Malaysia 3Institute of Science, Universiti Teknologi MARA, 40450 Shah Alam,Selangor, Malaysia * Email: [email protected]
2Advanced
ABSTRACT Study focuses on thermoluminescence (TL) characterisation of germanium doped silica glass fibre due to on-board kV x-ray source of a radiotherapy linear accelerator. Previous studies show that impurity of the glass fibers may contribute to a good TL response due to photon irradiation [1–3]. Therefore, study made used of various core diameters (11 µm, 50 µm and 113 µm) of commercial glass telecommunication fibers (CorActive High Tech, Canada). Irradiations were made using an x-ray tube arm attached to a radiotherapy linac providing 70 kVp, 100 kVp and 120 kVp photon energy at Advanced Medical and Dental Institute, USM (AMDI). The exposure time and current were varied in the range of 20 – 400 mAs to allow different dose integration. The measurement of TL response has been performed using TLD Reader Harshaw 3500 at AMDI. Linearity of TL has been observed with a correlation coefficient (r2) of better than 0.970 (at 95% confidence level). The least square fits show the change in TL yield, in counts per second per unit mass, obtained from 113 µm core diameter fibres irradiated at 100 kVp of photon to be greater than that of 11 µm core diameter fibre. With respect to energy response, the TL yield at 120 kVp decreases by ~7% compared to that at 70 kVp, primarily due to the lower mass energy absorption coefficient at higher energy. Gedoped silica glass fibers provide good dosimeter characteristics in term of dose linearity and energy dependence for the dose ranges studied. It shows promising application as a dosimeter for kV imaging during image guided radiotherapy (IGRT). Keywords: Thermoluminescence Dosimetry, Ge-Doped Silica Glass, X-Ray, Radiotherapy
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
The effect of collimator size variation on the beam radiation of Gamma Knife PerfexionTM based on Monte Carlo simulation Junios1, Irhas2, Novitrian3, E. Soediatmoko4, F. Haryanto5, and Z. Su’ud6 1,2,3,5,6 Faculty
of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jalan Ganesha 10 Bandung 40132, Indonesia 4 Gamma Knife Centre Indonesia, Siloam Hospital Lippo Karawaci, Tangerang, Banten 15811, Indonesia * Email: [email protected]
ABSTRACT Gamma Knife PerfexionTM (GKP) is a stereotactic surgical device which uses 60Co sources. To arrangement radiation of the beam, three sizes of the collimator of 4 mm, 8 mm, and 16 mm were used. Therefore, this study aimed to investigate radiation of the beam for each collimator using Monte Carlo (MC) simulation. In addition, radiation of the beam were investigated the beam profile and the mean energy by using fluence relative, collimator size deviation, and penumbra 20-80%. In the MC simulation, the source used phase space (Phsp) file from the previous simulation results which describe the source of encapsulated. Collimator geometry was simulated in a cylindrical shape. The output radiation of the beam (the second phsp file) were stored in a circular scoring plane with a radius of 1.4 cm at source surface distance (SSD) 16.7 cm. The simulation parameters were used 2.1 x 109 particles, electron cut off (ECUT) of 0.7 MeV, and photon cut off (PCUT) of 0.01 MeV. The results showed that there was an increase of relative fluence on the peak of beam profile at the collimator size of 4 mm, 8 mm, and 16 mm with the ratio of 25%, 50%, and 100%, respectively. The maximum mean energy for all of the size of collimators decreases by 0.01 MeV. Penumbra 20-80% on the mean energy in the 4 mm, 8 mm, and 16 mm collimators were 0.15 mm, 0.1 mm and 0.04 mm respectively. The Deviation of the full width at half maximum (FWHM) with the size of the collimator on the beam profile and the mean energy is the same, that is the collimator 4 mm, 8 mm, and 16 mm are 0.2, 0.1, and 0 respectively. Collimator size variation significantly influences the beam profile and mean energy.
Keywords: collimator size variation, beam radiation, Monte Carlo simulation.
REFERENCES 1. J Pipek, J Novotný, J Novotný Jr, and P Kozubíková (2014) A modular Geant4 model of Leksell Gamma Knife Perfexion™ Phys. Med. Biol. 59, 7609–7623 http://doi:10.1088/0031-9155/59/24/7609 2. Rogers, D. W. O., B. A. Faddegon, et al (1995) BEAM: A Monte Carlo code to simulate radiotherapy treatment units. Medical Physics. 22, 503-524 3. C.-M. Ma and D.W.O. Rogers (2017) BEAMDP User Manual NRCC Report PIRS-0509(C)revA. 1-33 4. D.W.O. Rogers, B. Walters, I. Kawrakow (2017) BEAMNRC User Manual NRCC Report PIRS-0509(A)revL. 1-289
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Application of 3-D Dense V-Net on Lung Image Automatic Segmentation Mohammad Haekal1,*, Freddy Haryanto2, and Idam Arif2 1Biophysics
and Medical Physics Laboratory, Department of Physics, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganeca no. 10, Bandung, West Java, Indonesia 40132 2Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganeca no. 10, Bandung, West Java, Indonesia 40132 * Email: [email protected]
ABSTRACT The automatic segmentation of medical images remains a challenging task in image processing field, especially for the segmentation of lung structures since homogeneity is not present in the lung region and the densities in the pulmonary structures are similar. The recent progress in the methods of automatic segmentation contributes to the construction of a fully-automated radiological image processing which can speed up the process of radiological image analysis by the clinician. This study aims to study the application of the 3-D dense V-net for automatic segmentation of lung images. The dense V-net, as compared to other deep learning architecture, possess two critical features for segmentation accuracy: the dense connections and the multi-scale V-network structure. The network had previously been applied to the segmentation of abdominal computed tomography (CT) and the segmentation of lung gross tumor volume. The dataset used in this study were supplied from The Cancer Imaging Archive (TCIA) database, specifically the Lung CT Segmentation Challenge 2017, containing the data of lung CT of 60 patients. The segmentation was divided into four categories: esophagus, heart, lungs, and spinal cords. The evaluation of the segmentation results obtained by this method was performed by using Dice similarity coefficient (DSC). The proposed application may be proved useful in constructing an automated system for the segmentation of lung images.
Keywords: medical image segmentation, lung segmentation, deep learning, v-net
REFERENCES 1. E. Gibson, F. Giganti, Y. Hu, et al., IEEE Trans. Med. Imaging 37(8), 1822-1834 (2018). 2. J. Ker, L. Wang, J. Rao, and T. Lim, IEEE Access 6, 9375-9389 (2017) 3. F. Milletari, N. Navab, and S.A. Ahmadi, “V-net: Fully convolutional neural networks for volumetric medical image segmentation” in the Fourth International Conference on 3D Vision, IEEE, 2016, pp. 565-571 4. J. Yang, H. Veeraraghavan, S.G. Armato III, et al, Med. Phys. 45(10), 4568-4581 (2018).
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Dosimetry for Intensity Modulated Radiotherapy (IMRT) Technique Using Ion Chamber Matrix (MatriXX-FFF) with Back Projection Method (Usual 6MV and 10MV) Pamuji Widodo1,2,*, Supriyanto A. P.3, and I Putu Susila4 Department of Physics, Faculty of Math and Science, University of Indonesia 2Instalation of Radiotherapy, Cancer Center of Dharmais Hospital 3Department of Physics, Faculty of Math and Science, University of Indonesia 4National Atom Nuclear Agency * Email: [email protected] 1
ABSTRACT Verification process has to be carried out every pre-treatment by using Intensity Modulated Radiotherapy (IMRT). One of dosimetry tools for IMRT is matrix detector type of ionization chamber that gives the result of dose measurement in real time, and is not required calibration periodically. But, the dosimetry has finite spatial resolution, depends on size and shape of detector, and occur the effect of secondary electron transpot from detector wall to detector volume, so that often gives the result of gamma parameter low enough. One of solutions, it can be solved by back projection method proposed by Poppe et al. In this research, that method could be applied by using kernel function of single field, then be used for variations of square field, no-BuildUp (NBU) and BuildUp (BU) condition, extendedSSD position, and IMRT case with 6 MV and 10 MV. Analysis of gamma parameter (Dose Difference/DD and Dose to Agreement/DTA) is used to verify the effectiveness of this method. The kernel function is obtained from square field of 4 cm by deconvolution from comparison of MatriXX-FFF and TPS. The results show increasing passing grade value for all of fields (0 % - 15.9 %, µ = 4.84 %, σ = 4.81 %), where the highest values are on square field of 4 cm and 5 cm at NBU and BU condition. All of those indicate the dependence kernel function to size of field. Application result of IMRT cases also give the same trend of increasing passing grade value. For the next, it needs to do research more about the relationship kernel function to size of field and the application of this method on IMRT case.
Keywords: verification, matrix-FFF (IBA), convolution, deconvolution, Dose Difference/DD, Dose to Agreement/DTA.
REFERENCES [1] Webb S, “The Physics of Conformal Radiotherapy,” Bristol Inst. Phys. Publ., 1997. [2] Tsai J S, W. D. E, L. M. N, W. J. K, F. M, D. T, K. B, K. M, and E. M. J, “Dosimetric verification of the dynamic intensity modulated radiation therapy of 92 patients,” Int. J. Radiat. Oncol. Biol. Phys, vol. 40, pp. 1213–30, 1998. [3] J. Y. Ting and L. W. Davis, “Dose verification for patients undergoing IMRT,” Med. Dosim, vol. 26 205–13, 2001.
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Performance Evaluation of Electronic Portal Imaging Device Used in Radiotherapy Armaldy Rafliansyah1*, Sugiyantari2, Rofikoh3 and Djarwani S. Soejoko4 4Physics
1,2,3RSUP Persahabatan, Jakarta, Indonesia Department, Faculty of Mathematics and Natural Sciences, University of Indonesia * Email: [email protected]
ABSTRACT The aim of this study is to evaluate the performance of electronic portal imaging device used for 2 years in radiotherapy. The device consists of A-Si panel, with detector area 25x25 at 160 SID. The evaluation use parameters in image quality are linearity, MTF (Modulation transfer Function) and Noise Power Spectrum (NPS) and Detective Quantum Efficiency (DQE). We use 2 methods for the measurement of MTF: Bar Phantom Method and Edge Method. NPS and DQE measurement done by acquire image at zero and various MU. All measurement was done for 6 MV and 10 MV photon beam. The image from measurement evaluated by imageJ and MATLAB to acquire the result. Linearity of device is excellent with the regression coefficient R = 0.995. The MTF of device is decreasing from 1.0 to 0.1 at spatial frequency 0 mm-1 to 0.6 mm-1. NPS of device described by signal acquired from image showed higher noise with radiation than noise without radiation (dark image). DQE of device decrease slightly with the increasing spatial frequency. This is our first measurement of the device’s image quality so we don’t have any benchmark to be compared of. So we use the result from literature and conclude that the performance of the device is still in good quality, proved by the similarity of result from the literature. As a routinely used and important device in verification of patient position in radiotherapy, this study shows a useful method and information to do quality assurance in radiotherapy.
Keywords: Electronic Portal Imaging Device, DQE, Image Quality, MTF, NPS, Quality Assurance
REFERENCES 1. F. Cremers et.al., Performance of Electronic Portal Imaging Devices (EPIDs) used in radiotherapy: Image Quality and Dose Measurements., Med. Phys. 31 (5), May 2004. 2. A. gopal et. al., A New Paradigm in Portal Imaging QA: fast Measurement of Modulation Transfer Function (MTF) and Detective Quantum Efficiency (DQE) Using Line-Pair Bar-Pattern, Medical Imaging 2007, proc. Of SPIE Vol. 6510,651048, (2007). 3. P. Sprawls, Physcial Principles of Medical Imaging, 2nd Edition, Madison, medical Physics Publishing Corporation, 1995.
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Evaluation Of Dosimetric Characterization Of Homemade Bolus For Radiation Therapy Chycilia Clara Chandra Carina1, Siti Aisyah1, Gandes Sekartaji1, Trimawarti Nazara1, Andreas Nainggolan2 and Endarko1,* 1Department
of Physics, Institut Teknologi Sepuluh Nopember, Kampus ITS Sukolilo – Surabaya 60111, East Java, Indonesia 2MRCCC Siloam Semanggi, 19230, Jakarta Selatan, Indonesia * Email: [email protected]
ABSTRACT The bolus is also known a tissue compensation that has material similar to body tissue and placed directly onto the skin surface for radiation therapy. This study aims to characterize and evaluate the synthesized homemade bolus using Natural Rubber, Paraffin Candle, Play-Doh, and Paraffin Wax Pure for radiation therapy using a photon beam. Several dosimetry properties of the synthesized of the bolus, including relative electron density (RED), transmission factor, attenuation coefficient, and percentage of surface dose (PSD), were investigated. All the synthesized bolus made with the same dimension of 11×11 cm2 with varies the thickness of 0.5, 1, and 1.5 cm. CT-Scan was used to measure relative electron density (RED) where as LINAC 2300iX with energies 6 and 10 MV were used to evaluate transmission factor, attenuation coefficient, and percentage of surface dose. The RED value of all bolus material is in accordance with the provisions of bolus as a tissue compensation of the human body, which is almost the same as the value of HU in breast organs, skin, fat and adult bones. Large transmission factors and attenuation coefficients of each bolus correspond to bolus from paraffin candles as the default bolus of the hospital. The maximum bolus dose value increases when compared to measurements without bolus. Keywords: bolus, natural rubber, RED, PSD.
REFERENCES 1. Babic, Steven et al. 2002. “Examination of Jeltrate Plus as a Tissue Equivalent Bolus Material.” Journal of applied clinical medical physics / American College of Medical Physics 3(3): 170–75. 2. Baskar, Rajamanickam, Kuo Ann Lee, Richard Yeo, and Kheng Wei Yeoh. 2012. “Cancer and Radiation Therapy: Current Advances and Future Directions.” International Journal of Medical Sciences 9(3): 193– 99. 3. Benoit, Jerome, Amy F. Pruitt, and Donald E. Thrall. 2009. “Effect of Wetness Level on the Suitability of Wet Gauze as a Substitute for Superflab® as a Bolus Material for Use with 6 MV Photons.” Veterinary Radiology and Ultrasound 50(5): 555–59. 4. Bhatki, Kashinath S. 2014. “Radiochemistry of Bismuth.” 8(Kommit): 343–53. 5. Eko Alan Pratama. 2017. “Kekuatan Tarik Karet Alam (Natural Rubber) Yang Dikogaulasi Dengan Menggunakan Buah Mengkudu (Morinda Citrifolia) Dan Tawas (Al2(SO4)3).” UNIVERSITAS LAMPUNG.
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
The Evaluation of the Dosimetric Characteristics of 10 MV Flattened and Unflattened Photon Beam in Inhomogenous Phantom Sitti Yani1,2,*, Indra Budiansah1, Mohamad Fahdillah Rhani3, and Freddy Haryanto1 1Faculty 2Faculty
of Mathematics and Natural Sciences, Institut Teknologi Bandung, West Java, 40132, Indonesia of Mathematics and Natural Sciences, Bogor Agricultural University, West Java, 16680, Indonesia 3Department of Radiology, Concord International Hospital, Singapore, 289891, Singapore * Email: [email protected]
ABSTRACT The Free Flattening Filter (FFF) beam can affect the characteristics of the linac output such as maximum dose depth, surface dose, dose in the fall-off area and doses outside the field because the beam hardening effect does not occur in the FFF linac head [1-4]. Therefore, this study aimed to study the influence of FFF beam on the dose distribution on inhomogeneous phantom using EGSnrc/DOSXYZnrc Monte Carlo package. In this study, Elekta Infinity 10 MV photon beam equipped with MLC Agility linear accelerator was used. Two types of virtual inhomogeneous phantom were built for PDDs and dose profiles measurement. The first phantom consisted of four layers: water (4 cm thickness), bone (2 cm thickness), lung tissue (5 cm thickness), and water (19 cm thickness). The second had a half-lung tissue slab and a half-bone slab (10 cm in thickness) on the left side in the water, respectively. The phantoms design was adopted by Onizuka et al. (2016) [5]. The PDD curve in the inhomogeneous phantom drops dramatically in the lung area for small exposure fields because the charged particles equilibrium does not achieve. The dose in the lung was higher than the dose in the water when the charged particles equilibrium was reached. Meanwhile, the dose in the bone is always lower than the dose in the water. The dose distribution of the FF and FFF beam in the inhomogeneous phantom was the same on a small field of exposure. However, differences in dose distribution are increasingly apparent for larger exposure fields. Keywords: Elekta Infinity, Free Flattening Filter, EGSnrc, inhomogeneous phantom.
REFERENCES 1. O. N. Vassiliev, U. Titt, F. Pönisch, S. F. Kry, R. Mohan, and M. T. Gillin, Physics in Medicine & Biology 51(7), 1907-1917 (2006). 2. J. Cashmore, Physics in Medicine & Biology 53(7), 1933-1946 (2008). 3. M. Mohammed, E. Chakir, H. Boukhal, S. Mroan, and T. El Bardouni, Journal of King Saud University Science 29(3), 371–79 (2017). 4. S. Sangeetha, and C. S. Sureka, Radiation Physics and Chemistry 135, 63–75 (2017). 5. R. Onizuka, F. Araki, T. Ohno, Y. Nakaguchi, Y. Kai, Y. Tomiyama, and K. Hioki, Radiological Physics and Technology 9 (1): 77–87 (2016).
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
ORAL PRESENTATION – DIAGNOSTIC RADIOLOGY
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Radiation Dose Measurements In Coronary CT Angiography (CCTA) Associated With Prospective ECG-Triggering Technique In Multidetector 640-Slice Scanner: A Comparison Study With National Dose Reference Level (NDRL) Mohd Shahril Mohd Shamsul1,2, Akmal Sabarudin1*, Hamzaini Abdul Hamid2, Norzailin Abu Bakar2, Oteh Maskon3, Muhmmad Khalis Abdul Karim4, 1Diagnostic
Imaging & Radiotherapy Program, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, 50300, Kuala Lumpur, Malaysia. 2Department of Radiology, Faculty of Medicine, UKM Medical Center, Jalan Yaacob Latif, Bandar Tun Razak, 56000 Kuala Lumpur, Malaysia. 3Department of Cardiology, Faculty of Medicine, UKM Medical Center, Jalan Yaacob Latif, Bandar Tun Razak, 56000 Kuala Lumpur, Malaysia. 4Department of Physics, Faculty of Sciences, Universiti Putra Malaysia, 43400 Seri Kembangan, Selangor, Malaysia. * Email: [email protected]
ABSTRACT A retrospective analysis was performed in patients undergoing prospective ECG-triggered coronary CT angiography (CCTA) with multidetector 640-slice CT with the aim of comparing radiation dose associated with different CT generations. The estimated effective dose of CCTA was also compared in multifactorial variables like genders, races and scan lengths. A total of 98 patients undergoing a prospective ECGtriggered CCTA examination were studied with estimated effective dose was at 5.70 ± 4.28 mSv. This result was significantly lower than that stated in the national dose reference level (NDRL) with 53% difference. This effective dose result was also compared to other scanner generation and remained lower than that in dual source 64-slice CT scanner with similar prospective ECG-triggered CCTA examination. Although the effective dose differed significantly in scan length of 160 mm versus 140 mm resulted with 5.90 ± 4.36 mSv versus 3.63 ± 2.75 mSv, there were no significant differences in effective dose estimation among genders and races. It is highly recommended that the practice of using prospective ECG-triggering CCTA with low scanning range and recent advancement of CT scanner technology showed low radiation dose compared to NDRL regardless of CCTA and calcium scoring examinations. Keywords: prospective ECG-triggering, coronary CT angiography, effective dose, dose reference level
REFERENCES 1. N. R. Mollet, F. Cademartiri, C. A. G. van Mieghem, G. Runza, E. P. McFadden, T. Baks, P. W. Serruys, G. P. Krestin, and P. J. de Feyter, Circulation 112, 2318 (2005). 2. G. L. Raff, M. J. Gallagher, W. W. O'Neill, and J. A. Goldstein, J Am Coll Cardiol 46, 552 (2005). 3. S. Achenbach, et al., Eur J Radiol 57, 331 (2006). 4. M. J. Budoff, et al., Circulation 114, 1761 (2006). 5. E. P. Efstathopoulos, N. L. Kelekis, I. Pantos, E. Brountzos, S. Argentos, J. Greb´a, D. Ziaka, D. G. Katritsis, and I. Seimenis, Phys Med Biol 54, 5209 (2009). 6. M. J. Budoff, et al., Circulation 114, 1761 (2006).
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The 17th South-East Asia Congress of Medical Physics (SEACOMP) in conjunction with the 3rd Annual Scientific Meeting on Medical Physics and Biophysics (PIT-FMB), 8 – 10 August 2019, Bali, Indonesia
Lifetime Risk Estimation Of Thyroid Cancer In Paediatric CT Examinations. N A Muhammad1 , M K A Karim2* and WONG, J.H.D3 and H A Hassan4 1&2Department
of Physics, Faculty of Science, University Putra Malaysia 43400 Serdang, Selangor, Malaysia; Imaging Department, University Malaya Medical Center (UMMC) 59100 Petaling Jaya, Kuala Lumpur, MALAYSIA. 4Department of Imaging, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia 43400 UPM Serdang, Selangor, Malaysia; *Email: [email protected]
3Biomedical
ABSTRACT Children's cell is more susceptible to radiation compared with adult and considered to be higher risk. Recent reports indicate that there is a significant increase in radiation-induced risk worldwide, particularly to thyroid. The thyroid is one of many important organs that helps in stabilizing hormones in the human body. The frequency of nonoptimization of scanning parameters in CT examination is concerning for radiation-induced risk to thyroid gland. Therefore, the aim of this study is to estimate the radiation absorbed dose received by paediatric patients and to estimate the probability of thyroid cancer risk in paediatric population. Data were retrospectively collected from one single institution for a period between January 2016 and December 2018. Patient demographic was collected from the CT console (PACS) and recorded in a standardized form.145 subjects were included in this study where subject’s age was less than 15 years old and underwent for CT brain, CT thorax and CT chest-abdomen-pelvis (CT CAP) examinations. The study was categorized into 3 groups ( 1-