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Papadakis AE, Giannakaki V, Stratakis J, Myronakis M, Zaidi H, Damilakis J. Digital phantom versus patient-specific radiation dosimetry in adult routine thorax CT examinations. J Appl Clin Med Phys 2024; 25:e14389. [PMID: 38778565 DOI: 10.1002/acm2.14389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 04/09/2024] [Accepted: 04/23/2024] [Indexed: 05/25/2024] Open
Abstract
PURPOSE The aim of this study was to compare the organ doses assessed through a digital phantom-based and a patient specific-based dosimetric tool in adult routine thorax computed tomography (CT) examinations with reference to physical dose measurements performed in anthropomorphic phantoms. METHODS Two Monte Carlo based dose calculation tools were used to assess organ doses in routine adult thorax CT examinations. These were a digital phantom-based dosimetry tool (NCICT, National Cancer Institute, USA) and a patient-specific individualized dosimetry tool (ImpactMC, CT Imaging GmbH, Germany). Digital phantoms and patients were classified in four groups according to their water equivalent diameter (Dw). Normalized to volume computed tomography dose index (CTDIvol), organ dose was assessed for lungs, esophagus, heart, breast, active bone marrow, and skin. Organ doses were compared to measurements performed using thermoluminescent detectors (TLDs) in two physical anthropomorphic phantoms that simulate the average adult individual as a male (Alderson Research Labs, USA) and as a female (ATOM Phantoms, USA). RESULTS The average percent difference of NCICT to TLD and ImpactMC to TLD dose measurements across all organs in both sexes was 13% and 6%, respectively. The average ± 1 standard deviation in dose values across all organs with NCICT, ImpactMC, and TLDs was ± 0.06 (mGy/mGy), ± 0.19 (mGy/mGy), and ± 0.13 (mGy/mGy), respectively. Organ doses decreased with increasing Dw in both NCICT and ImpactMC. CONCLUSION Organ doses estimated with ImpactMC were in closer agreement to TLDs compared to NCICT. This may be attributed to the inherent property of ImpactMC methodology to generate phantoms that resemble the realistic anatomy of the examined patient as opposed to NCICT methodology that incorporates an anatomical discrepancy between phantoms and patients.
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Affiliation(s)
- Antonios E Papadakis
- University Hospital of Heraklion, Medical Physics Department, Stavrakia, Heraklion, Crete, Greece
| | - Vassiliki Giannakaki
- University Hospital of Heraklion, Medical Physics Department, Stavrakia, Heraklion, Crete, Greece
| | - John Stratakis
- University Hospital of Heraklion, Medical Physics Department, Stavrakia, Heraklion, Crete, Greece
| | - Marios Myronakis
- University Hospital of Heraklion, Medical Physics Department, Stavrakia, Heraklion, Crete, Greece
| | - Habib Zaidi
- Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, Geneva, Switzerland
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
- Department of Nuclear Medicine, University of Southern Denmark, Odense, Denmark
- University Research and Innovation Center, Obuda University, Budapest, Hungary
| | - John Damilakis
- University of Crete, Medical School, Medical Physics Department, Stavrakia, Heraklion, Crete, Greece
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Wu Y, Wang Z, Chu Y, Peng R, Peng H, Yang H, Guo K, Zhang J. Current Research Status of Respiratory Motion for Thorax and Abdominal Treatment: A Systematic Review. Biomimetics (Basel) 2024; 9:170. [PMID: 38534855 DOI: 10.3390/biomimetics9030170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 02/29/2024] [Accepted: 03/09/2024] [Indexed: 03/28/2024] Open
Abstract
Malignant tumors have become one of the serious public health problems in human safety and health, among which the chest and abdomen diseases account for the largest proportion. Early diagnosis and treatment can effectively improve the survival rate of patients. However, respiratory motion in the chest and abdomen can lead to uncertainty in the shape, volume, and location of the tumor, making treatment of the chest and abdomen difficult. Therefore, compensation for respiratory motion is very important in clinical treatment. The purpose of this review was to discuss the research and development of respiratory movement monitoring and prediction in thoracic and abdominal surgery, as well as introduce the current research status. The integration of modern respiratory motion compensation technology with advanced sensor detection technology, medical-image-guided therapy, and artificial intelligence technology is discussed and analyzed. The future research direction of intraoperative thoracic and abdominal respiratory motion compensation should be non-invasive, non-contact, use a low dose, and involve intelligent development. The complexity of the surgical environment, the constraints on the accuracy of existing image guidance devices, and the latency of data transmission are all present technical challenges.
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Affiliation(s)
- Yuwen Wu
- Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, China
| | - Zhisen Wang
- Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, China
- School of Biomedical Engineering (Suzhou), Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China
| | - Yuyi Chu
- Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, China
| | - Renyuan Peng
- Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, China
- School of Biomedical Engineering (Suzhou), Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China
| | - Haoran Peng
- Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, China
- School of Biomedical Engineering (Suzhou), Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China
| | - Hongbo Yang
- Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, China
- School of Biomedical Engineering (Suzhou), Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China
| | - Kai Guo
- Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, China
- School of Biomedical Engineering (Suzhou), Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China
| | - Juzhong Zhang
- Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, China
- School of Biomedical Engineering (Suzhou), Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China
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Choi C, Shin B, Yeom YS, Kim CH, Bolch WE, Jokisch DW, Han H, Lee C, Chung BS. Development of Respiratory Tract Organs for ICRP Pediatric Mesh-type Reference Computational Phantoms. HEALTH PHYSICS 2023; 125:434-445. [PMID: 37823824 DOI: 10.1097/hp.0000000000001740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/13/2023]
Abstract
ABSTRACT As part of the activities of the International Commission on Radiological Protection (ICRP) Task Group 103, the present study developed a new set of respiratory tract organs consisting of the extrathoracic, bronchial, bronchiolar, and alveolar-interstitial regions for newborn, 1-, 5-, 10-, and 15-y-old males and females for use in pediatric mesh-type reference computational phantoms. The developed respiratory tract organs, while preserving the original topologies of those of the pediatric voxel-type reference computational phantoms of ICRP Publication 143, have improved anatomy and detailed structure and also include μm-thick target and source regions prescribed in ICRP Publication 66. The dosimetric impact of the developed respiratory tract organs was investigated by calculating the specific absorbed fraction for internal electron exposures, which were then compared with the ICRP Task Group 96 values. The results showed that except for the alveolar-interstitial region as a source region, the pediatric mesh phantoms showed larger specific absorbed fractions than the Task Group 96 values. The maximum difference was a factor of ~3.5 for the extrathoracic-2 basal cell and surface as target and source regions, respectively. These results reflect the differences in the target masses and geometry caused by the anatomical enhancement of the pediatric mesh phantoms. For the alveolar-interstitial region as a source region, the pediatric mesh phantoms showed larger values for low energy ranges and lower values with increasing energies, owing to the differences in the size and shape of the alveolar-interstitial region.
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Affiliation(s)
- Chansoo Choi
- J Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL
| | - Bangho Shin
- Department of Nuclear Engineering, Hanyang University, Seoul, Republic of Korea
| | - Yeon Soo Yeom
- Department of Radiation Convergence Engineering, Yonsei University, Wonju, Republic of Korea
| | - Chan Hyeong Kim
- Department of Nuclear Engineering, Hanyang University, Seoul, Republic of Korea
| | - Wesley E Bolch
- J Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL
| | | | - Haegin Han
- Department of Nuclear Engineering, Hanyang University, Seoul, Republic of Korea
| | - Choonsik Lee
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD
| | - Beom Sun Chung
- Department of Anatomy, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea
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Pieters H, van Staden JA, du Plessis FCP, du Raan H. Validation of a Monte Carlo simulated cardiac phantom for planar and SPECT studies. Phys Med 2023; 111:102617. [PMID: 37290226 DOI: 10.1016/j.ejmp.2023.102617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 04/19/2023] [Accepted: 05/30/2023] [Indexed: 06/10/2023] Open
Abstract
PURPOSE This work aimed to validate Monte Carlo (MC) simulated cardiac phantoms for the evaluation of planar- and SPECT-gated-blood-pool (GBP-P and GBP-S) studies. METHODS A comparison of gamma camera system performance criteria measurements (energy resolution, spatial resolution, sensitivity) with MC simulations was conducted. Furthermore, the accuracy of measured and simulated volumes of two stereolithography-printed cardiac phantoms (based on 4D-XCAT phantoms) was assessed. Finally, the simulated GBP-P and GBP-S XCAT studies were validated by comparing calculated left ventricular ejection fraction (LVEF) and ventricle volume values with known parameters. RESULTS The simulated performance criteria compared well with measured values (energy resolution difference: 0.1 ± 0.10%; spatial resolution (full width at half maximum) difference ≤ 0.5 ± 0.8 mm and system sensitivity difference ≤ 6.2 ± 0.62cps/MBq). The measured and simulated cardiac phantoms were in good agreement; the left anterior oblique views compared well. This is supported by line profiles through these phantoms and on average, simulated counts were 5.8% lower than measured counts. The LVEF values calculated from the GBP-P and GBP-S simulated data differ from known values (2.8 ± 0.64% and 0.8 ± 0.52%). The differences between the known XCAT LV volumes and simulated GBP-S calculated volumes were -1.2 ± 1.91 ml and -1.5 ± 0.96 ml for the end-diastolic and end-systolic volumes. CONCLUSION The MC-simulated cardiac phantom has been validated successfully. Stereolithography-printing allows researchers to create clinically realistic organ phantoms and is a valuable tool for validating MC simulations and clinical software. By conducting GBP simulation studies with various XCAT models, the user will be able to generate GBP-P and GBP-S databases for future software evaluation.
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Affiliation(s)
- Hané Pieters
- Department of Medical Physics, University of the Free State, PO Box 339, Bloemfontein 9301, South Africa.
| | - Johannes A van Staden
- Department of Medical Physics, University of the Free State, PO Box 339, Bloemfontein 9301, South Africa.
| | - Frederik C P du Plessis
- Department of Medical Physics, University of the Free State, PO Box 339, Bloemfontein 9301, South Africa.
| | - Hanlie du Raan
- Department of Medical Physics, University of the Free State, PO Box 339, Bloemfontein 9301, South Africa.
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Griffin KT, Eckerman KF, Manger RP, Jokisch DW, Bolch WE, Hertel NE. Specific Absorbed Fractions for Spontaneous Fission Neutron Emitters in the ICRP Reference Pediatric Voxel Phantom Series. HEALTH PHYSICS 2022; 123:278-286. [PMID: 35776943 PMCID: PMC9444919 DOI: 10.1097/hp.0000000000001594] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
ABSTRACT Specific absorbed fractions (SAFs) are key components in the workflow of internal exposure assessment following the intake of a radionuclide, allowing quick conversion of particle energy released in a source region to the expected absorbed dose in target regions throughout the body. For data completeness, SAFs for spontaneous fission neutron emitters are currently needed for the recently adopted ICRP reference pediatric voxel phantom series. With 77 source regions within each reference individual and 28 radionuclides decaying via spontaneous fission, full Monte Carlo simulation requires significant computation time. In order to reduce this burden, a novel method for neutron SAF estimation was undertaken. The Monte Carlo N-Particle version 6.1 (MCNP6) simulation package was chosen to simulate the 252 Cf Watt fission neutron spectrum originating from 15 source regions in each phantom; dose estimation within 41 target tissues allowed for assessment of the SAF value for each source-target pair. For the remaining source regions, chord length distributions were computed using MATLAB code to determine the separation between the source-target pairs within the pediatric phantom series. These distance distributions were used in conjunction with a 252 Cf neutron dose point kernel calculated in soft tissue, which was modified to account for the source region's depth from the surface of the body. Lastly, the 252 Cf SAF dataset was extended to the other 27 spontaneous fission neutron emitters based on differences in the Watt fission spectrum parameters of each radionuclide. This methodology has been shown to accurately estimate spontaneous fission neutron SAFs to within 20% of the Monte Carlo estimated value for most source-target pairs in the ICRP reference pediatric series.
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Affiliation(s)
| | | | - Ryan P Manger
- Department of Radiation Medicine and Applied Sciences, School of Medicine, University of California San Diego, San Diego, CA
| | | | - Wesley E Bolch
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL
| | - Nolan E Hertel
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA
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6
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Lawson M, Berk K, Badawy M, Qi Y, Kuganesan A, Metcalfe P. Comparison of organ and effective dose estimations from different Monte Carlo simulation-based software methods in infant CT and comparison with direct phantom measurements. J Appl Clin Med Phys 2022; 23:e13625. [PMID: 35522240 PMCID: PMC9194989 DOI: 10.1002/acm2.13625] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Revised: 03/09/2022] [Accepted: 04/11/2022] [Indexed: 11/30/2022] Open
Abstract
Purpose Computational dosimetry software is routinely used to evaluate the organ and effective doses from computed tomography (CT) examinations. Studies have shown a significant variation in dose estimates between software in adult cohorts, and few studies have evaluated software for pediatric dose estimates. This study aims to compare the primary organ and effective doses estimated by four commercially available CT dosimetry software to thermoluminescent dosimeter (TLD) measurements in a 1‐year‐old phantom. Methods One hundred fifteen calibrated LiF (Mg, Cu, P)‐TLD 100‐H chips were embedded within an anthropomorphic phantom representing a 1‐year‐old child at positions that matched the approximate location of organs within an infant. The phantom was scanned under three protocols, each with whole‐body coverage. The mean absorbed doses from 25 radiosensitive organs and skeletal tissues were determined from the TLD readings. Effective doses for each of the protocols were subsequently calculated using ICRP 103 formalism. Dose estimates by the four Monte Carlo–based dose calculation systems were determined and compared to the directly measured doses. Results Most organ doses determined by computation dosimetry software aligned to phantom measurements within 20%. Additionally, comparisons between effective doses are calculated using computational and direct measurement methods aligned within 20% across the three protocols. Significant variances were found in bone surface dose estimations among dosimetry methods, likely caused by differences in bone tissue modeling. Conclusion All four‐dosimetry software evaluated in this study provide adequate primary organ and effective dose estimations. Users should be aware, however, of the possible estimated uncertainty associated with each of the programs.
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Affiliation(s)
- Michael Lawson
- Monash Health Imaging, Monash Health, Clayton, Victoria, Australia.,Centre for Medical Radiation Physics, School of Physics, Faculty of Engineering and Information Sciences, University of Wollongong, Wollongong, New South Wales, Australia
| | - Kemal Berk
- Department of Physical Sciences, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia
| | - Mohamed Badawy
- Monash Health Imaging, Monash Health, Clayton, Victoria, Australia.,Department of Medical Imaging and Radiation Sciences, School of Primary and Allied Health Care, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria, Australia
| | - Yujin Qi
- Centre for Medical Radiation Physics, School of Physics, Faculty of Engineering and Information Sciences, University of Wollongong, Wollongong, New South Wales, Australia
| | - Ahilan Kuganesan
- Monash Health Imaging, Monash Health, Clayton, Victoria, Australia
| | - Peter Metcalfe
- Centre for Medical Radiation Physics, School of Physics, Faculty of Engineering and Information Sciences, University of Wollongong, Wollongong, New South Wales, Australia
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Yin Y, Wang X, Kong X, Zhang W, Wang Y, Mao Y, Wang J, Jia T, Tu Y, Zhang B, Sun L. Physical dosimetric reconstruction of a case of large area back skin injury due to overexposure in an interventional procedure. RADIATION MEDICINE AND PROTECTION 2022. [DOI: 10.1016/j.radmp.2022.02.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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Akhavanallaf A, Fayad H, Salimi Y, Aly A, Kharita H, Al Naemi H, Zaidi H. An update on computational anthropomorphic anatomical models. Digit Health 2022; 8:20552076221111941. [PMID: 35847523 PMCID: PMC9277432 DOI: 10.1177/20552076221111941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 06/19/2022] [Indexed: 11/15/2022] Open
Abstract
The prevalent availability of high-performance computing coupled with validated
computerized simulation platforms as open-source packages have motivated
progress in the development of realistic anthropomorphic computational models of
the human anatomy. The main application of these advanced tools focused on
imaging physics and computational internal/external radiation dosimetry
research. This paper provides an updated review of state-of-the-art developments
and recent advances in the design of sophisticated computational models of the
human anatomy with a particular focus on their use in radiation dosimetry
calculations. The consolidation of flexible and realistic computational models
with biological data and accurate radiation transport modeling tools enables the
capability to produce dosimetric data reflecting actual setup in clinical
setting. These simulation methodologies and results are helpful resources for
the medical physics and medical imaging communities and are expected to impact
the fields of medical imaging and dosimetry calculations profoundly.
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Affiliation(s)
- Azadeh Akhavanallaf
- Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, Geneva, Switzerland
| | - Hadi Fayad
- Hamad Medical Corporation, Doha, Qatar
- Weill Cornell Medicine, Doha, Qatar
| | - Yazdan Salimi
- Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, Geneva, Switzerland
| | - Antar Aly
- Hamad Medical Corporation, Doha, Qatar
- Weill Cornell Medicine, Doha, Qatar
| | | | - Huda Al Naemi
- Hamad Medical Corporation, Doha, Qatar
- Weill Cornell Medicine, Doha, Qatar
| | - Habib Zaidi
- Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, Geneva, Switzerland
- Geneva University Neurocenter, Geneva University, Geneva, Switzerland
- Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
- Department of Nuclear Medicine, University of Southern Denmark, Odense, Denmark
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Cheon B, Lee SH, Han MC, Min CH, Han H, Kim CH, Kim JS. Development of a novel program for conversion from tetrahedral-mesh-based phantoms to DICOM dataset for radiation treatment planning: TET2DICOM. J Appl Clin Med Phys 2022; 23:e13448. [PMID: 34633736 PMCID: PMC8803294 DOI: 10.1002/acm2.13448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 09/22/2021] [Accepted: 09/25/2021] [Indexed: 11/11/2022] Open
Abstract
PURPOSE Tetrahedral mesh (TM)-based computational human phantoms have recently been developed for evaluation of exposure dose with the merit of precisely representing human anatomy and the changing posture freely. However, conversion of recently developed TM phantoms to the Digital Imaging and Communications in Medicine (DICOM) file format, which can be utilized in the clinic, has not been attempted. The aim of this study was to develop a technique, called TET2DICOM, to convert the TM phantoms to DICOM datasets for accurate treatment planning. MATERIALS AND METHODS The TM phantoms were sampled in voxel form to generate the DICOM computed tomography images. The DICOM-radiotherapy structure was defined based on the contour data. To evaluate TET2DICOM, the shape distortion of the TM phantoms during the conversion process was assessed, and the converted DICOM dataset was implemented in a commercial treatment planning system (TPS). RESULTS The volume difference between the TM phantoms and the converted DICOM dataset was evaluated as less than about 0.1% in each organ. Subsequently, the converted DICOM dataset was successfully implemented in MIM (MIM Software Inc., Cleveland, USA, version 6.5.6) and RayStation (RaySearch Laboratories, Stockholm, Sweden, version 5.0). Additionally, the various possibilities of clinical application of the program were confirmed using a deformed TM phantom in various postures. CONCLUSION In conclusion, the TM phantom, currently the most advanced computational phantom, can be implemented in a commercial TPS and this technique can enable various TM-based applications, such as evaluation of secondary cancer risk in radiotherapy.
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Affiliation(s)
- Bo‐Wi Cheon
- Department of Radiation Convergence EngineeringYonsei UniversityWonjuKorea
| | - Se Hyung Lee
- Department of Nuclear EngineeringHanyang UniversitySeoulKorea
- Department of Radiation OncologyBundang Jesaeng General HospitalSeongnamKorea
| | - Min Cheol Han
- Department of Radiation OncologyYonsei University College of MedicineSeoulKorea
| | - Chul Hee Min
- Department of Radiation Convergence EngineeringYonsei UniversityWonjuKorea
| | - Haegin Han
- Department of Nuclear EngineeringHanyang UniversitySeoulKorea
| | - Chan Hyeong Kim
- Department of Nuclear EngineeringHanyang UniversitySeoulKorea
| | - Jin Sung Kim
- Department of Radiation OncologyYonsei University College of MedicineSeoulKorea
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Andersson J, Bednarek DR, Bolch W, Boltz T, Bosmans H, Gislason-Lee AJ, Granberg C, Hellstrom M, Kanal K, McDonagh E, Paden R, Pavlicek W, Khodadadegan Y, Torresin A, Trianni A, Zamora D. Estimation of patient skin dose in fluoroscopy: summary of a joint report by AAPM TG357 and EFOMP. Med Phys 2021; 48:e671-e696. [PMID: 33930183 DOI: 10.1002/mp.14910] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Revised: 04/04/2021] [Accepted: 04/23/2021] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND Physicians use fixed C-arm fluoroscopy equipment with many interventional radiological and cardiological procedures. The associated effective dose to a patient is generally considered low risk, as the benefit-risk ratio is almost certainly highly favorable. However, X-ray-induced skin injuries may occur due to high absorbed patient skin doses from complex fluoroscopically guided interventions (FGI). Suitable action levels for patient-specific follow-up could improve the clinical practice. There is a need for a refined metric regarding follow-up of X-ray-induced patient injuries and the knowledge gap regarding skin dose-related patient information from fluoroscopy devices must be filled. The most useful metric to indicate a risk of erythema, epilation or greater skin injury that also includes actionable information is the peak skin dose, that is, the largest dose to a region of skin. MATERIALS AND METHODS The report is based on a comprehensive review of best practices and methods to estimate peak skin dose found in the scientific literature and situates the importance of the Digital Imaging and Communication in Medicine (DICOM) standard detailing pertinent information contained in the Radiation Dose Structured Report (RDSR) and DICOM image headers for FGI devices. Furthermore, the expertise of the task group members and consultants have been used to bridge and discuss different methods and associated available DICOM information for peak skin dose estimation. RESULTS The report contributes an extensive summary and discussion of the current state of the art in estimating peak skin dose with FGI procedures with regard to methodology and DICOM information. Improvements in skin dose estimation efforts with more refined DICOM information are suggested and discussed. CONCLUSIONS The endeavor of skin dose estimation is greatly aided by the continuing efforts of the scientific medical physics community, the numerous technology enhancements, the dose-controlling features provided by the FGI device manufacturers, and the emergence and greater availability of the DICOM RDSR. Refined and new dosimetry systems continue to evolve and form the infrastructure for further improvements in accuracy. Dose-related content and information systems capable of handling big data are emerging for patient dose monitoring and quality assurance tools for large-scale multihospital enterprises.
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Affiliation(s)
- Jonas Andersson
- Department of Radiation Sciences, Radiation Physics, Umeå University, SE-901 85, Umeå, Sweden
| | - Daniel R Bednarek
- State University of New York, 875 Ellicott St, Buffalo, NY, 14203-1070, USA
| | - Wesley Bolch
- University of Florida, 1275 Center Drive, Gainesville, FL, 32611-6131, USA
| | - Thomas Boltz
- Orange Factor Imaging Physicists, 4035 E Captain Dreyfus Ave, Phoenix, AZ, 85032, USA
| | - Hilde Bosmans
- University of Leuven, Herestraat 49, Leuven, B-3000, Belgium
| | | | - Christoffer Granberg
- Department of Radiation Sciences, Radiation Physics, Umeå University, SE-901 85, Umeå, Sweden
| | - Max Hellstrom
- Department of Radiation Sciences, Radiation Physics, Umeå University, SE-901 85, Umeå, Sweden
| | - Kalpana Kanal
- University of Washington Medical Center, 1959 NE Pacific Street, Seattle, WA, 98195, USA
| | - Ed McDonagh
- Joint Department of Physics, The Royal Marsden NHS Foundation Trust, Fulham Road, London, SW3 6JJ, UK
| | - Robert Paden
- Mayo Clinic, 5777 East Mayo Blvd, Phoenix, AZ, 85054, USA
| | | | - Yasaman Khodadadegan
- Progressive Insurance, Customer Relation Management, 6300 Wilson Mills Rd., Mayfield Village, OH, 44143, USA
| | - Alberto Torresin
- Niguarda Ca'Granda Hospital, Via Leon Battista Alberti 5, Milano, 20149, Italy
| | - Annalisa Trianni
- Udine University Hospital, Piazzale S. Maria Della Misericordia, n. 15, 33100, Udine, Italy
| | - David Zamora
- University of Washington Medical Center, 6852 31st Ave NE, Seattle, WA, 98115-7245, USA
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11
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Fum WKS, Wong JHD, Tan LK. Monte Carlo-based patient internal dosimetry in fluoroscopy-guided interventional procedures: A review. Phys Med 2021; 84:228-240. [PMID: 33849785 DOI: 10.1016/j.ejmp.2021.03.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 02/18/2021] [Accepted: 03/03/2021] [Indexed: 11/27/2022] Open
Abstract
PURPOSE This systematic review aims to understand the dose estimation approaches and their major challenges. Specifically, we focused on state-of-the-art Monte Carlo (MC) methods in fluoroscopy-guided interventional procedures. METHODS All relevant studies were identified through keyword searches in electronic databases from inception until September 2020. The searched publications were reviewed, categorised and analysed based on their respective methodology. RESULTS Hundred and one publications were identified which utilised existing MC-based applications/programs or customised MC simulations. Two outstanding challenges were identified that contribute to uncertainties in the virtual simulation reconstruction. The first challenge involves the use of anatomical models to represent individuals. Currently, phantom libraries best balance the needs of clinical practicality with those of specificity. However, mismatches of anatomical variations including body size and organ shape can create significant discrepancies in dose estimations. The second challenge is that the exact positioning of the patient relative to the beam is generally unknown. Most dose prediction models assume the patient is located centrally on the examination couch, which can lead to significant errors. CONCLUSION The continuing rise of computing power suggests a near future where MC methods become practical for routine clinical dosimetry. Dynamic, deformable phantoms help to improve patient specificity, but at present are only limited to adjustment of gross body volume. Dynamic internal organ displacement or reshaping is likely the next logical frontier. Image-based alignment is probably the most promising solution to enable this, but it must be automated to be clinically practical.
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Affiliation(s)
- Wilbur K S Fum
- Department of Biomedical Imaging, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia; Division of Radiological Sciences, Singapore General Hospital, Outram Rd, Singapore 169608, Singapore.
| | - Jeannie Hsiu Ding Wong
- Department of Biomedical Imaging, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia.
| | - Li Kuo Tan
- Department of Biomedical Imaging, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia.
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12
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Kim CH, Yeom YS, Petoussi-Henss N, Zankl M, Bolch WE, Lee C, Choi C, Nguyen TT, Eckerman K, Kim HS, Han MC, Qiu R, Chung BS, Han H, Shin B. ICRP Publication 145: Adult Mesh-Type Reference Computational Phantoms. Ann ICRP 2020; 49:13-201. [PMID: 33231095 DOI: 10.1177/0146645319893605] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
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13
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Han H, Yeom YS, Choi C, Moon S, Shin B, Ha S, Kim CH. POLY2TET: a computer program for conversion of computational human phantoms from polygonal mesh to tetrahedral mesh. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2020; 40:962-979. [PMID: 32964861 DOI: 10.1088/1361-6498/abb360] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
As a geometrical format for computational human phantoms, tetrahedral mesh (TM) is known to have significant advantages over polygonal mesh (PM), including higher compatibility with Monte Carlo radiation transport codes, higher computation speed, and the capability of modeling heterogeneous density variation in an organ of the phantom. In the present study, a computer program named POLY2TET was developed to convert the format of computational human phantoms from PM to TM and generate a sample source code or input file, as applicable, for the converted phantom to be used in some general-purpose Monte Carlo radiation transport codes (i.e. Geant4, PHITS, and MCNP6). The developed program was then tested using four existing high-fidelity PM phantoms. The computation speed, memory requirement, and initialisation time of the generated TM phantoms were also measured and compared with those of the original PM phantoms in Geant4. From the results of our test, it was concluded that the developed program successfully converts PM phantoms into the TM format. The organ doses calculated using the generated TM phantom for the three Monte Carlo codes all produced essentially identical dose values to those for the original PM phantoms in Geant4. The comparison of computation speed showed that compared to the original PM phantoms in Geant4, the TM phantoms in the three Monte Carlo codes were much faster in transporting the particles considered in the present study, i.e. by up to ∼2600 times for electron beams simulated in PHITS. The comparison of the memory requirement showed that the TM phantoms required more memory than the original PM phantoms, but, except for MCNP6, the memory required for the TM phantoms was still less than 12 GB, which typically is available in personal computers these days. For MCNP6, the required memory was much higher, i.e. 60-70 GB.
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Affiliation(s)
- Haegin Han
- Department of Nuclear Engineering, Hanyang University, Seoul, Republic of Korea
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14
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Golikov V, Druzhinina P. Technical Note: Patient‐weight dependence of the effective dose conversion coefficients for diagnostic x‐ray imaging procedures. Med Phys 2020; 47:5366-5372. [DOI: 10.1002/mp.14446] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 07/24/2020] [Accepted: 08/02/2020] [Indexed: 01/26/2023] Open
Affiliation(s)
- Vladislav Golikov
- St‐Petersburg Research Institute of Radiation Hygiene after Professor P.V. Ramzaev Mira str. 8 St‐Petersburg197101 Russian Federation
| | - Polina Druzhinina
- St‐Petersburg Research Institute of Radiation Hygiene after Professor P.V. Ramzaev Mira str. 8 St‐Petersburg197101 Russian Federation
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15
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Zhang H, Sun S, Lu H, Liu Y. CONSTRUCTION AND APPLICATION OF BREP PHANTOM FOR CHINESE WOMEN OF CHILDBEARING AGE IN RADIATION PROTECTION. RADIATION PROTECTION DOSIMETRY 2020; 189:407-419. [PMID: 32318714 DOI: 10.1093/rpd/ncaa056] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 03/16/2020] [Accepted: 04/04/2020] [Indexed: 06/11/2023]
Abstract
The purpose of this study is to construct boundary representation (BREP) phantom for Chinese women of childbearing age, to estimate the external radiation dose and to analyze radiation protection scheme. The BREP phantom for Chinese women of childbearing age was constructed by image segmentation, 3D reconstruction, non-uniform rational B-spline surface construction and voxelization. The photon-irradiated organ absorbed dose-conversion coefficients (DCCK) of the three female specific organs and the photon effective dose-conversion coefficient (ECCK) were calculated by Monte-Carlo method. The results showed that age, body fat-tissue thickness, direction and area of irradiation, organ location and volume all affected the dose of women specific organs when receiving medical exposure. In the case of ensuring the quality of the diagnosis, radiation protection for female specific organs can be achieved by organ dose modulation techniques and reducing exposure area or volume.
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Affiliation(s)
- Haowei Zhang
- College of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai 200093, People's Republic of China
| | - Si Sun
- College of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai 200093, People's Republic of China
| | - Heqing Lu
- Department of Medical Equipment for Shanghai First Maternity and Infant Hospital, Tongji University School of Medicine, Shanghai 201204, People's Republic of China
| | - Ying Liu
- College of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai 200093, People's Republic of China
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16
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Ho H, Dahmen U, Hunter P. An in silico rat liver atlas. Comput Methods Biomech Biomed Engin 2020; 23:597-600. [PMID: 32310673 DOI: 10.1080/10255842.2020.1754404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Numerous hepatic function, disease and pharmacological experiments are performed on rat livers. Many of these experiments rely on an accurate understanding of the rat liver anatomy. In this short paper, we present an in silico rat liver atlas which is constructed from the micro-CT images of explanted rat livers. The atlas consists of the parametric mesh for four liver lobes and a paracaval portion. 1D and 3D cubic Hermite mesh are used to represent the rat liver vessels and lobes, respectively. We discuss potential applications that can be performed from the in silico atlas.
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Affiliation(s)
- Harvey Ho
- Auckland Bioengineering Institute, The University of Auckland, New Zealand
| | - Uta Dahmen
- Department of General, Visceral and Vascular Surgery, Jena University, Germany
| | - Peter Hunter
- Auckland Bioengineering Institute, The University of Auckland, New Zealand
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17
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Papadimitroulas P, Balomenos A, Kopsinis Y, Loudos G, Alexakos C, Karnabatidis D, Kagadis GC, Kostou T, Chatzipapas K, Visvikis D, Mountris KA, Jaouen V, Katsanos K, Diamantopoulos A, Apostolopoulos D. A Review on Personalized Pediatric Dosimetry Applications Using Advanced Computational Tools. IEEE TRANSACTIONS ON RADIATION AND PLASMA MEDICAL SCIENCES 2019. [DOI: 10.1109/trpms.2018.2876562] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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18
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Han MC, Ku Y, Lee HS, Yeom YS, Han H, Kim CH. New calculation method for 3D dose distribution in tetrahedral-mesh phantoms in Geant4. Phys Med 2019; 66:97-103. [PMID: 31585335 DOI: 10.1016/j.ejmp.2019.09.239] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 08/27/2019] [Accepted: 09/23/2019] [Indexed: 11/18/2022] Open
Abstract
The tetrahedral-mesh (TM) geometry, which is a very promising geometry for computational human phantoms, has a limitation in 3D dose distribution calculation for medical applications. Even though Geant4 provides the read-out geometry for calculating 3D dose distribution in the TM geometry, this method significantly slows down the computation speed. In the present study, we developed a new method, called Moving Voxel-based Dose-Distribution Calculator (MVDDC), to rapidly calculate a 3D dose distribution in a TM geometry. To evaluate the performance of the MVDDC method, a simple TM cubic phantom and a human phantom were implemented in Geant4. Subsequently, the phantoms were irradiated with proton spot beams under various conditions, and the obtained results were compared with those of the read-out geometry method. The results show that there is no significant difference between the dose distributions calculated using the new method and the read-out geometry method. With respect to the computational performance, the speeds of simulations using the MVDDC were approximately 1.4-2.7 times faster than those of the simulations using the read-out geometry method.
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Affiliation(s)
- Min Cheol Han
- Department of Radiation Oncology, Yonsei University College of Medicine, Seoul 03722, South Korea
| | - Youngmo Ku
- Department of Nuclear Engineering, Hanyang University, Seoul 04763, South Korea
| | - Hyun Su Lee
- Department of Nuclear Engineering, Hanyang University, Seoul 04763, South Korea
| | - Yeon Soo Yeom
- Division of Cancer Epidemiology & Genetics, National Cancer Institute, MD 20892-9760, USA
| | - Haegin Han
- Department of Nuclear Engineering, Hanyang University, Seoul 04763, South Korea
| | - Chan Hyeong Kim
- Department of Nuclear Engineering, Hanyang University, Seoul 04763, South Korea.
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19
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Lee C, Badal A, Yeom YS, Griffin K, McMillan D. Dosimetric impact of voxel resolutions of computational human phantoms for external photon exposure. Biomed Phys Eng Express 2019; 5:065002. [PMID: 38500848 PMCID: PMC10948017 DOI: 10.1088/2057-1976/ab2850] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Several research teams have developed computational phantoms in polygonal-mesh (PM) and/or Non-Uniform Rational B-Spline format, but it has not been systematically evaluated if the existing voxel phantoms are still dosimetrically valid. We created three voxel phantoms with the resolutions of 1,000, 125, and 1 mm3 and simulated the irradiation in antero-posterior geometry with photons of 0.1, 1, and 10 MeV using voxel Monte Carlo codes, and compared the energy deposition to their organs/tissues with the values from the original PM phantom using mesh Monte Carlo codes. The coefficient of variation in energy deposition overall showed about five-fold decrease as the voxel resolution increased but differences were mostly less than 5% for any voxel resolution. We conclude that PM phantoms and mesh Monte Carlo techniques may not be necessary for external photon exposure (0.1 - 10 MeV) and the existing voxel phantoms can provide enough dosimetric accuracy in those exposure conditions.
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Affiliation(s)
- Choonsik Lee
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD
| | - Andreu Badal
- Division of Imaging, Diagnostics and Software Reliability, OSEL, CDRH, Food and Drug Administration, Silver Spring, MD
| | - Yeon Soo Yeom
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD
| | - Keith Griffin
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD
| | - Dayton McMillan
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD
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20
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Griffin KT, Mille MM, Pelletier C, Gopalakrishnan M, Jung JW, Lee C, Kalapurakal J, Pyakuryal A, Lee C. Conversion of computational human phantoms into DICOM-RT for normal tissue dose assessment in radiotherapy patients. Phys Med Biol 2019; 64:13NT02. [PMID: 31158829 DOI: 10.1088/1361-6560/ab2670] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Radiotherapy (RT) treatment planning systems (TPS) are designed for the fast calculation of dose to the tumor bed and nearby organs at risk using x-ray computed tomography (CT) images. However, CT images for a patient are typically available for only a small portion of the body, and in some cases, such as for retrospective epidemiological studies, no images may be available at all. When dose to organs that lie out-of-scan must be estimated, a convenient alternative for the unknown patient anatomy is to use a matching whole-body computational phantom as a surrogate. The purpose of the current work is to connect such computational phantoms to commercial RT TPS for retrospective organ dose estimation. A custom software with graphical user interface (GUI), called the DICOM-RT Generator, was developed in MATLAB to convert voxel computational phantoms into the digital imaging and communications in medicine radiotherapy (DICOM-RT) format, compatible with commercial TPS. DICOM CT image sets for the phantoms are created via a density-to-Hounsfield unit (HU) conversion curve. Accompanying structure sets containing the organ contours are automatically generated by tracing binary masks of user-specified organs on each phantom CT slice. The software was tested on a library of body size-dependent phantoms, the International Commission on Radiological Protection reference phantoms, and a canine voxel phantom, taking only a few minutes per conversion. The resulting DICOM-RT files were tested on several commercial TPS. As an example application, a library of converted phantoms was used to estimate organ doses for members of the National Wilms Tumor Study (NWTS) cohort. The converted phantom library, in DICOM format, and a standalone MATLAB-compiled executable of the DICOM-RT Generator are available for others to use for research purposes (http://ncidose.cancer.gov).
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Affiliation(s)
- Keith T Griffin
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD 20850, United States of America
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21
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Baptista M, Di Maria S, Vieira S, Santos J, Pereira J, Pereira M, Vaz P. Dosimetric assessment of the exposure of radiotherapy patients due to cone-beam CT procedures. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2019; 58:21-37. [PMID: 30392077 DOI: 10.1007/s00411-018-0760-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2018] [Accepted: 10/30/2018] [Indexed: 06/08/2023]
Abstract
Cone-beam computed tomography (CBCT) is widely used for pre-treatment verification and patient setup in image-guided radiation therapy (IGRT). CBCT imaging is employed daily and several times per patient, resulting in potentially high cumulative imaging doses to healthy tissues that surround exposed target organs. Computed tomography dose index (CTDI) is the parameter used by CBCT equipment as indication of the radiation output to patients. This study aimed to increase the knowledge on the relation between CBCT organ doses and weighted CTDI (CTDIW) for a thorax scanning protocol. A CBCT system was modelled using the Monte Carlo (MC) radiation transport program MCNPX2.7.0. Simulation results were validated against half-value layer (HVL), axial beam profile, patient skin dose (PSD) and CTDI measurements. For organ dose calculations, a male voxel phantom ("Golem") was implemented with the CBCT scanner computational model. After a successful MC model validation with measurements, a systematic comparison was performed between organ doses (and their distribution) and CTDI dosimetry concepts [CTDIW and cumulative dose quantities f100(150) and [Formula: see text]]. The results obtained show that CBCT organ doses vary between 1.2 ± 0.1 mGy and 3.3 ± 0.2 mGy for organs located within the primary beam. It was also verified that CTDIW allows prediction of absorbed doses to tissues at distances of about 5 cm from the isocentre of the CBCT system, whereas f100(150) allows prediction of organ doses at distances of about 10 cm from the isocentre, independently from its location. This study demonstrates that these dosimetric concepts are suitable methods that easily allow a good approximation of the additional CBCT imaging doses during a typical lung cancer IGRT treatment.
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Affiliation(s)
- Mariana Baptista
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Campus Tecnológico e Nuclear, Estrada Nacional 10, km 139,7, 2695-066, Bobadela LRS, Portugal.
| | - Salvatore Di Maria
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Campus Tecnológico e Nuclear, Estrada Nacional 10, km 139,7, 2695-066, Bobadela LRS, Portugal
| | - Sandra Vieira
- Fundação Champalimaud, Centro Clínico Champalimaud, Avenida de Brasília, 1400-038, Lisbon, Portugal
| | - Joana Santos
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Campus Tecnológico e Nuclear, Estrada Nacional 10, km 139,7, 2695-066, Bobadela LRS, Portugal
- Instituto Politécnico de Coimbra, ESTESC, DIMR, Rua 5 de Outubro, 3046-854, Coimbra, Portugal
| | - Joana Pereira
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Campus Tecnológico e Nuclear, Estrada Nacional 10, km 139,7, 2695-066, Bobadela LRS, Portugal
- Laboratório de Protecção e Segurança Radiológica, Instituto Superior Técnico, Campus Tecnológico e Nuclear, Estrada Nacional 10, km 139,7, 2695-066, Bobadela LRS, Portugal
| | - Miguel Pereira
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Campus Tecnológico e Nuclear, Estrada Nacional 10, km 139,7, 2695-066, Bobadela LRS, Portugal
- Laboratório de Protecção e Segurança Radiológica, Instituto Superior Técnico, Campus Tecnológico e Nuclear, Estrada Nacional 10, km 139,7, 2695-066, Bobadela LRS, Portugal
| | - Pedro Vaz
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Campus Tecnológico e Nuclear, Estrada Nacional 10, km 139,7, 2695-066, Bobadela LRS, Portugal
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22
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George Xu X. Innovations in Computer Technologies Have Impacted Radiation Dosimetry Through Anatomically Realistic Phantoms and Fast Monte Carlo Simulations. HEALTH PHYSICS 2019; 116:263-275. [PMID: 30585974 DOI: 10.1097/hp.0000000000001007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Radiological physics principles have not changed in the past 60 y when computer technologies advanced exponentially. The research field of anatomical modeling for the purpose of radiation dose calculations has experienced an explosion in activity in the past two decades. Such an exciting advancement is due to the feasibility of creating three-dimensional geometric details of the human anatomy from tomographic imaging and of performing Monte Carlo radiation transport simulations on increasingly fast and cheap personal computers. The advent of a new type of high-performance computing hardware in recent years-graphics processing units-has made it feasible to carry out time-consuming Monte Carlo calculations at near real-time speeds. This paper introduces the history of three generations of computational human phantoms (the stylized medical internal radiation dosimetry-type phantoms, the voxelized tomographic phantoms, and the boundary representation deformable phantoms) and new development of the graphics processing unit-based Monte Carlo radiation dose calculations. Examples are given for research projects performed by my students in applying computational phantoms and a new Monte Carlo code, ARCHER, to problems in radiation protection, imaging, and radiotherapy. Finally, the paper discusses challenges and future opportunities for research.
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Affiliation(s)
- X George Xu
- JEC 5049, Rensselaer Polytechnic Institute, 110 8th St., Troy, NY 12180
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23
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Kainz W, Neufeld E, Bolch WE, Graff CG, Kim CH, Kuster N, Lloyd B, Morrison T, Segars P, Yeom YS, Zankl M, Xu XG, Tsui BMW. Advances in Computational Human Phantoms and Their Applications in Biomedical Engineering - A Topical Review. IEEE TRANSACTIONS ON RADIATION AND PLASMA MEDICAL SCIENCES 2019; 3:1-23. [PMID: 30740582 PMCID: PMC6362464 DOI: 10.1109/trpms.2018.2883437] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Over the past decades, significant improvements have been made in the field of computational human phantoms (CHPs) and their applications in biomedical engineering. Their sophistication has dramatically increased. The very first CHPs were composed of simple geometric volumes, e.g., cylinders and spheres, while current CHPs have a high resolution, cover a substantial range of the patient population, have high anatomical accuracy, are poseable, morphable, and are augmented with various details to perform functionalized computations. Advances in imaging techniques and semi-automated segmentation tools allow fast and personalized development of CHPs. These advances open the door to quickly develop personalized CHPs, inherently including the disease of the patient. Because many of these CHPs are increasingly providing data for regulatory submissions of various medical devices, the validity, anatomical accuracy, and availability to cover the entire patient population is of utmost importance. The article is organized into two main sections: the first section reviews the different modeling techniques used to create CHPs, whereas the second section discusses various applications of CHPs in biomedical engineering. Each topic gives an overview, a brief history, recent developments, and an outlook into the future.
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Affiliation(s)
- Wolfgang Kainz
- Food and Drug Administration (FDA), Center for Devices and Radiological Health (CDRH), Silver Spring, MD 20993 USA
| | - Esra Neufeld
- Foundation for Research on Information Technologies in Society (IT'IS), Zurich, Switzerland
| | | | - Christian G Graff
- Food and Drug Administration (FDA), Center for Devices and Radiological Health (CDRH), Silver Spring, MD 20993 USA
| | | | - Niels Kuster
- Swiss Federal Institute of Technology, ETH Zürich, and the Foundation for Research on Information Technologies in Society (IT'IS), Zürich, Switzerland
| | - Bryn Lloyd
- Foundation for Research on Information Technologies in Society (IT'IS), Zurich, Switzerland
| | - Tina Morrison
- Food and Drug Administration (FDA), Center for Devices and Radiological Health (CDRH), Silver Spring, MD 20993 USA
| | | | | | - Maria Zankl
- Helmholtz Zentrum München German Research Center for Environmental Health, Munich, Germany
| | - X George Xu
- Rensselaer Polytechnic Institute, Troy, NY, USA
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24
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Belinato W, Silva RM, Perini AP, Neves LP, Santos CJ, Souza DN, Santos WS. Monte Carlo dosimetric evaluation in PET exams for patients with different BMI and heights. Radiat Phys Chem Oxf Engl 1993 2018. [DOI: 10.1016/j.radphyschem.2018.05.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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25
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Kim CH, Yeom YS, Nguyen TT, Han MC, Choi C, Lee H, Han H, Shin B, Lee JK, Kim HS, Zankl M, Petoussi-Henss N, Bolch WE, Lee C, Chung BS, Qiu R, Eckerman K. New mesh-type phantoms and their dosimetric applications, including emergencies. Ann ICRP 2018; 47:45-62. [PMID: 29651869 DOI: 10.1177/0146645318756231] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Committee 2 of the International Commission on Radiological Protection (ICRP) has constructed mesh-type adult reference computational phantoms by converting the voxel-type ICRP Publication 110 adult reference computational phantoms to a high-quality mesh format, and adding those tissues that were below the image resolution of the voxel phantoms and therefore not included in the Publication 110 phantoms. The new mesh phantoms include all the necessary source and target tissues for effective dose calculations, including the 8-40-µm-thick target layers of the alimentary and respiratory tract organs, thereby obviating the need for supplemental organ-specific stylised models (e.g. respiratory airways, alimentary tract organ walls and stem cell layers, lens of the eye, and skin basal layer). To see the impact of the new mesh-type reference phantoms, dose coefficients for some selected external and internal exposures were calculated and compared with the current reference values in ICRP Publications 116 and 133, which were calculated by employing the Publication 110 phantoms and the supplemental stylised models. The new mesh phantoms were also used to calculate dose coefficients for industrial radiography sources near the body, which can be used to estimate the organ doses of the worker who is accidentally exposed by an industrial radiography source; in these calculations, the mesh phantoms were deformed to reflect the size of the worker, and also to evaluate the effect of posture on dose coefficients.
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Affiliation(s)
- C H Kim
- a Department of Nuclear Engineering, Hanyang University, 04763, 222 Wangsimni-ro, Seongdong-gu, Seoul, Republic of Korea
| | - Y S Yeom
- a Department of Nuclear Engineering, Hanyang University, 04763, 222 Wangsimni-ro, Seongdong-gu, Seoul, Republic of Korea
| | - T T Nguyen
- a Department of Nuclear Engineering, Hanyang University, 04763, 222 Wangsimni-ro, Seongdong-gu, Seoul, Republic of Korea
| | - M C Han
- a Department of Nuclear Engineering, Hanyang University, 04763, 222 Wangsimni-ro, Seongdong-gu, Seoul, Republic of Korea
| | - C Choi
- a Department of Nuclear Engineering, Hanyang University, 04763, 222 Wangsimni-ro, Seongdong-gu, Seoul, Republic of Korea
| | - H Lee
- a Department of Nuclear Engineering, Hanyang University, 04763, 222 Wangsimni-ro, Seongdong-gu, Seoul, Republic of Korea
| | - H Han
- a Department of Nuclear Engineering, Hanyang University, 04763, 222 Wangsimni-ro, Seongdong-gu, Seoul, Republic of Korea
| | - B Shin
- a Department of Nuclear Engineering, Hanyang University, 04763, 222 Wangsimni-ro, Seongdong-gu, Seoul, Republic of Korea
| | - J-K Lee
- a Department of Nuclear Engineering, Hanyang University, 04763, 222 Wangsimni-ro, Seongdong-gu, Seoul, Republic of Korea
| | - H S Kim
- b Korea Institute of Radiological & Medical Sciences, Republic of Korea
| | - M Zankl
- c Helmholtz Zentrum München Deutsches Forschungszentrum für Gesundheit und Umwelt, Germany
| | - N Petoussi-Henss
- c Helmholtz Zentrum München Deutsches Forschungszentrum für Gesundheit und Umwelt, Germany
| | | | - C Lee
- e National Cancer Institute, USA
| | - B S Chung
- f Ajou University School of Medicine, Republic of Korea
| | - R Qiu
- g Tsinghua University, P.R. China
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26
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Han MC, Yeom YS, Lee HS, Shin B, Kim CH, Furuta T. Multi-threading performance of Geant4, MCNP6, and PHITS Monte Carlo codes for tetrahedral-mesh geometry. Phys Med Biol 2018; 63:09NT02. [PMID: 29633956 DOI: 10.1088/1361-6560/aabd20] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
In this study, the multi-threading performance of the Geant4, MCNP6, and PHITS codes was evaluated as a function of the number of threads (N) and the complexity of the tetrahedral-mesh phantom. For this, three tetrahedral-mesh phantoms of varying complexity (simple, moderately complex, and highly complex) were prepared and implemented in the three different Monte Carlo codes, in photon and neutron transport simulations. Subsequently, for each case, the initialization time, calculation time, and memory usage were measured as a function of the number of threads used in the simulation. It was found that for all codes, the initialization time significantly increased with the complexity of the phantom, but not with the number of threads. Geant4 exhibited much longer initialization time than the other codes, especially for the complex phantom (MRCP). The improvement of computation speed due to the use of a multi-threaded code was calculated as the speed-up factor, the ratio of the computation speed on a multi-threaded code to the computation speed on a single-threaded code. Geant4 showed the best multi-threading performance among the codes considered in this study, with the speed-up factor almost linearly increasing with the number of threads, reaching ~30 when N = 40. PHITS and MCNP6 showed a much smaller increase of the speed-up factor with the number of threads. For PHITS, the speed-up factors were low when N = 40. For MCNP6, the increase of the speed-up factors was better, but they were still less than ~10 when N = 40. As for memory usage, Geant4 was found to use more memory than the other codes. In addition, compared to that of the other codes, the memory usage of Geant4 more rapidly increased with the number of threads, reaching as high as ~74 GB when N = 40 for the complex phantom (MRCP). It is notable that compared to that of the other codes, the memory usage of PHITS was much lower, regardless of both the complexity of the phantom and the number of threads, hardly increasing with the number of threads for the MRCP.
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Affiliation(s)
- Min Cheol Han
- INFN Sezione di Genova, Via Dodecaneso 33, Genova 16146, Italy. Department of Nuclear Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 04763, Republic of Korea
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Han M, Lee AK, Choi HD, Jung YW, Park JS. Averaged head phantoms from magnetic resonance images of Korean children and young adults. Phys Med Biol 2018; 63:035003. [PMID: 29239853 DOI: 10.1088/1361-6560/aaa1c7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Increased use of mobile phones raises concerns about the health risks of electromagnetic radiation. Phantom heads are routinely used for radiofrequency dosimetry simulations, and the purpose of this study was to construct averaged phantom heads for children and young adults. Using magnetic resonance images (MRI), sectioned cadaver images, and a hybrid approach, we initially built template phantoms representing 6-, 9-, 12-, 15-year-old children and young adults. Our subsequent approach revised the template phantoms using 29 averaged items that were identified by averaging the MRI data from 500 children and young adults. In females, the brain size and cranium thickness peaked in the early teens and then decreased. This is contrary to what was observed in males, where brain size and cranium thicknesses either plateaued or grew continuously. The overall shape of brains was spherical in children and became ellipsoidal by adulthood. In this study, we devised a method to build averaged phantom heads by constructing surface and voxel models. The surface model could be used for phantom manipulation, whereas the voxel model could be used for compliance test of specific absorption rate (SAR) for users of mobile phones or other electronic devices.
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Affiliation(s)
- Miran Han
- Department of Radiology, Ajou University School of Medicine and Hospital, Suwon, Republic of Korea
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Baptista M, Di Maria S, Vieira S, Vaz P. Entrance surface dose distribution and organ dose assessment for cone-beam computed tomography using measurements and Monte Carlo simulations with voxel phantoms. Radiat Phys Chem Oxf Engl 1993 2017. [DOI: 10.1016/j.radphyschem.2017.02.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Liu C, Liang X. Calculation of the Photon Dose Conversion Coefficient Based on Boundary Representation Phantoms of Different Postures. HEALTH PHYSICS 2017; 113:353-362. [PMID: 28961583 DOI: 10.1097/hp.0000000000000712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Based on the hybrid Chinese reference adult female phantom, the Chinese reference female boundary representation (BREP) phantoms involving sitting, walking, and squatting postures were established. The photon effective dose conversion coefficient (ECCK) and some organ absorbed dose conversion coefficients (DCCK) were calculated under six standard irradiation geometries, and the irradiation source included 20 monoenergetic photon energies ranging from 0.01 MeV to 10 MeV. The results indicate that the postures, location of the organs, and irradiation geometries have an impact on the dose conversion coefficients. With the same irradiation geometry, the DCCKs of different organs are different; when the photon energy is from 0.02 MeV to 0.1 MeV, significant differences exist in the DCCK of phantoms of various postures, and the maximum relative deviation is 80%. For the ECCKs, there are greater differences among phantoms of various postures with the same irradiation geometry when the photon energy is from 0.02 MeV to 0.05 MeV, and the maximum relative deviation is about 20%.
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Affiliation(s)
- Chunyu Liu
- *Environment Engineering Center, China Nuclear Power Technology Research Institute, Shenzhen 518028, China
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Implications of using a 50-μm-thick skin target layer in skin dose coefficient calculation for photons, protons, and helium ions. NUCLEAR ENGINEERING AND TECHNOLOGY 2017. [DOI: 10.1016/j.net.2017.06.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Satoh D, Furuta T, Takahashi F, Lee C, Bolch WE. Simulation study of personal dose equivalent for external exposure to radioactive cesium distributed in soil. J NUCL SCI TECHNOL 2017. [DOI: 10.1080/00223131.2017.1344157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Daiki Satoh
- Nuclear Science and Engineering Center, Japan Atomic Energy Agency, Ibaraki, , Japan
| | - Takuya Furuta
- Nuclear Science and Engineering Center, Japan Atomic Energy Agency, Ibaraki, , Japan
| | - Fumiaki Takahashi
- Nuclear Science and Engineering Center, Japan Atomic Energy Agency, Ibaraki, , Japan
| | - Choonsik Lee
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD, USA
| | - Wesley Emmett Bolch
- Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
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Xie T, Kuster N, Zaidi H. Effects of body habitus on internal radiation dose calculations using the 5-year-old anthropomorphic male models. Phys Med Biol 2017; 62:6185-6206. [PMID: 28703120 DOI: 10.1088/1361-6560/aa75b4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Computational phantoms are commonly used in internal radiation dosimetry to assess the amount and distribution pattern of energy deposited in various parts of the human body from different internal radiation sources. Radiation dose assessments are commonly performed on predetermined reference computational phantoms while the argument for individualized patient-specific radiation dosimetry exists. This study aims to evaluate the influence of body habitus on internal dosimetry and to quantify the uncertainties in dose estimation correlated with the use of fixed reference models. The 5-year-old IT'IS male phantom was modified to match target anthropometric parameters, including body weight, body height and sitting height/stature ratio (SSR), determined from reference databases, thus enabling the creation of 125 5-year-old habitus-dependent male phantoms with 10th, 25th, 50th, 75th and 90th percentile body morphometries. We evaluated the absorbed fractions and the mean absorbed dose to the target region per unit cumulative activity in the source region (S-values) of F-18 in 46 source regions for the generated 125 anthropomorphic 5-year-old hybrid male phantoms using the Monte Carlo N-Particle eXtended general purpose Monte Carlo transport code and calculated the absorbed dose and effective dose of five 18F-labelled radiotracers for children of various habitus. For most organs, the S-value of F-18 presents stronger statistical correlations with body weight, standing height and sitting height than BMI and SSR. The self-absorbed fraction and self-absorbed S-values of F-18 and the absorbed dose and effective dose of 18F-labelled radiotracers present with the strongest statistical correlations with body weight. For 18F-Amino acids, 18F-Brain receptor substances, 18F-FDG, 18F-L-DOPA and 18F-FBPA, the mean absolute effective dose differences between phantoms of different habitus and fixed reference models are 11.4%, 11.3%, 10.8%, 13.3% and 11.4%, respectively. Total body weight, standing height and sitting height have considerable effects on human internal dosimetry. Radiation dose calculations for individual subjects using the most closely matched habitus-dependent computational phantom should be considered as an alternative to improve the accuracy of the estimates.
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Affiliation(s)
- Tianwu Xie
- Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, 1211 Geneva 4, Switzerland
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Alves MC, Santos WS, Lee C, Bolch WE, Hunt JG, Júnior ABC. Conversion Coefficients for Proton Beams using Standing and Sitting Male Hybrid Computational Phantom Calculated in Idealized Irradiation Geometries. RADIATION PROTECTION DOSIMETRY 2017; 175:75-86. [PMID: 27664429 PMCID: PMC6257014 DOI: 10.1093/rpd/ncw271] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2016] [Revised: 08/21/2016] [Accepted: 08/31/2016] [Indexed: 06/06/2023]
Abstract
The aim of this study was the calculation of conversion coefficients for absorbed doses per fluence (DT/Φ) using the sitting and standing male hybrid phantom (UFH/NCI) exposure to monoenergetic protons with energy ranging from 2 MeV to 10 GeV. Sex-averaged effective dose per fluence (E/Φ) using the results of DT/Φ for the male and female hybrid phantom in standing and sitting postures were also calculated. Results of E/Φ of UFH/NCI standing phantom were also compared with tabulated effective dose conversion coefficients provided in ICRP publication 116. To develop an exposure scenario implementing the male UFH/NCI phantom in sitting and standing postures was used the radiation transport code MCNPX. Whole-body irradiations were performed using the recommended irradiation geometries by ICRP publication 116 antero-posterior (AP), postero-anterior (PA), right and left lateral, rotational (ROT) and isotropic (ISO). In most organs, the conversion coefficients DT/Φ were similar for both postures. However, relative differences were significant for organs located in the lower abdominal region, such as prostate, testes and urinary bladder, especially in the AP geometry. Results of effective dose conversion coefficients were 18% higher in the standing posture of the UFH/NCI phantom, especially below 100 MeV in AP and PA. In lateral geometry, the conversion coefficients values below 20 MeV were 16% higher in the sitting posture. In ROT geometry, the differences were below 10%, for almost all energies. In ISO geometry, the differences in E/Φ were negligible. The results of E/Φ of UFH/NCI phantom were in general below the results of the conversion coefficients provided in ICRP publication 116.
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Affiliation(s)
- M. C. Alves
- Departamento de Física, Universidade Federal de Sergipe; Campus Prof. José Aloísio de Campos, 49.100-000, São Cristóvão – SE, Brazil
| | - W. S. Santos
- Instituto de Física, Universidade Federal de Uberlândia (INFIS/UFU), Caixa Postal 593, 38400-902 Uberlândia, MG, Brazil
| | - C. Lee
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institute of Health, Bethesda, MD 20852, USA
| | - W. E. Bolch
- Department of Nuclear and Radiological Engineering, University of Florida, Gainesville, FL 32611-8300, USA
| | - J. G. Hunt
- Dosimetry Division, Instituto de Radioproteção e Dosimetria, Rio de Janeiro, RJ 22783-127, Brazil
| | - A. B. Carvalho Júnior
- Departamento de Física, Universidade Federal de Sergipe; Campus Prof. José Aloísio de Campos, 49.100-000, São Cristóvão – SE, Brazil
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Kim HS, Yeom YS, Nguyen TT, Choi C, Han MC, Lee JK, Kim CH, Zankl M, Petoussi-Henss N, Bolch WE, Lee C, Qiu R, Eckerman K, Chung BS. Inclusion of thin target and source regions in alimentary and respiratory tract systems of mesh-type ICRP adult reference phantoms. Phys Med Biol 2017; 62:2132-2152. [DOI: 10.1088/1361-6560/aa5b72] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Alves MC, Galeano DC, Santos WS, Lee C, Bolch WE, Hunt JG, da Silva AX, Carvalho AB. Comparison of the effective dose rate to aircrew members using hybrid computational phantoms in standing and sitting postures. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2016; 36:885-901. [PMID: 27798410 DOI: 10.1088/0952-4746/36/4/885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Aircraft crew members are occupationally exposed to considerable levels of cosmic radiation at flight altitudes. Since aircrew (pilots and passengers) are in the sitting posture for most of the time during flight, and up to now there has been no data on the effective dose rate calculated for aircrew dosimetry in flight altitude using a sitting phantom, we therefore calculated the effective dose rate using a phantom in the sitting and standing postures in order to compare the influence of the posture on the radiation protection of aircrew members. We found that although the better description of the posture in which the aircrews are exposed, the results of the effective dose rate calculated with the phantom in the sitting posture were very similar to the results of the phantom in the standing posture. In fact we observed only a 1% difference. These findings indicate the adequacy of the use of dose conversion coefficients for the phantom in the standing posture in aircrew dosimetry. We also validated our results comparing the effective dose rate obtained using the standing phantom with values reported in the literature. It was observed that the results presented in this study are in good agreement with other authors (the differences are below 30%) who have measured and calculated effective dose rates using different phantoms.
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Affiliation(s)
- M C Alves
- Departamento de Física, Universidade Federal de Sergipe; Campus Prof. José Aloísio de Campos, 49.100-000, São Cristóvão, SE, Brazil
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Yeom YS, Wang ZJ, Nguyen TT, Kim HS, Choi C, Han MC, Kim CH, Lee JK, Chung BS, Zankl M, Petoussi-Henss N, Bolch WE, Lee C. Development of skeletal system for mesh-type ICRP reference adult phantoms. Phys Med Biol 2016; 61:7054-7073. [PMID: 27648514 DOI: 10.1088/0031-9155/61/19/7054] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The reference adult computational phantoms of the international commission on radiological protection (ICRP) described in Publication 110 are voxel-type computational phantoms based on whole-body computed tomography (CT) images of adult male and female patients. The voxel resolutions of these phantoms are in the order of a few millimeters and smaller tissues such as the eye lens, the skin, and the walls of some organs cannot be properly defined in the phantoms, resulting in limitations in dose coefficient calculations for weakly penetrating radiations. In order to address the limitations of the ICRP-110 phantoms, an ICRP Task Group has been recently formulated and the voxel phantoms are now being converted to a high-quality mesh format. As a part of the conversion project, in the present study, the skeleton models, one of the most important and complex organs of the body, were constructed. The constructed skeleton models were then tested by calculating red bone marrow (RBM) and endosteum dose coefficients (DCs) for broad parallel beams of photons and electrons and comparing the calculated values with those of the original ICRP-110 phantoms. The results show that for the photon exposures, there is a generally good agreement in the DCs between the mesh-type phantoms and the original voxel-type ICRP-110 phantoms; that is, the dose discrepancies were less than 7% in all cases except for the 0.03 MeV cases, for which the maximum difference was 14%. On the other hand, for the electron exposures (⩽4 MeV), the DCs of the mesh-type phantoms deviate from those of the ICRP-110 phantoms by up to ~1600 times at 0.03 MeV, which is indeed due to the improvement of the skeletal anatomy of the developed skeleton mesh models.
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Affiliation(s)
- Yeon Soo Yeom
- Department of Nuclear Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 04763, Korea
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Hadad K, Saeedi-Moghadam M, Zeinali-Rafsanjani B. Voxel dosimetry: Comparison of MCNPX and DOSXYZnrc Monte Carlo codes in patient specific phantom calculations. Technol Health Care 2016; 25:29-35. [PMID: 27447407 DOI: 10.3233/thc-161240] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
INTRODUCTION Dose evaluation with two Monte Carlo codes using patient specific voxel phantom is presented in this paper. We employ both MCNPX and DOSXYZnrc to perform dosimetry for mathematical voxel phantoms generated by our in-house developed voxel phantom generator and EGSnrc/CTCreate respectively. MATERIAL AND METHOD Our case study was a 2.5 × 2.4 × 2.4 cm3 tumor in the middle lobe of right lung of a male patient exposed to 6MV parallel beam. In order to compare these Monte Carlo codes with together gross tumor volume (GTV) and organ at risks (OAR) doses and dose volume histograms (DVH) were calculated. RESULTS Comparing the mean absorbed dose results (in Gy) from both codes indicates that gross tumor volume, heart and spinal cord have 2% to 10% difference. The 10% difference between the codes were from the spinal cord region where was not in the therapy beam and it just received the scatter radiation. The dose volume DVH obtained from DOSXYZnrc results demonstrate a milder slope compared with MCNPX DVHs. CONCLUSION It was revealed that MCNPX has some advantages in comparison to DOSXYZnrc, but it is important to consider that for equal precision in voxel dosimetry calculation, DOSXYZnrc runs faster than MCNPX and it is a great advantage.
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Affiliation(s)
- Kamal Hadad
- Department of Nuclear Engineering, School of Mechanical Engineering, Shiraz University, Shiraz, Iran
| | - Mahdi Saeedi-Moghadam
- Medical Imaging Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Banafsheh Zeinali-Rafsanjani
- Medical Imaging Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.,Nuclear Medicine and Molecular Imaging Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
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Yeom YS, Kim HS, Nguyen TT, Choi C, Han MC, Kim CH, Lee JK, Zankl M, Petoussi-Henss N, Bolch WE, Lee C, Chung BS. New small-intestine modeling method for surface-based computational human phantoms. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2016; 36:230-245. [PMID: 27007802 DOI: 10.1088/0952-4746/36/2/230] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
When converting voxel phantoms to a surface format, the small intestine (SI), which is usually not accurately represented in a voxel phantom due to its complex and irregular shape on one hand and the limited voxel resolutions on the other, cannot be directly converted to a high-quality surface model. Currently, stylized pipe models are used instead, but they are strongly influenced by developer's subjectivity, resulting in unacceptable geometric and dosimetric inconsistencies. In this paper, we propose a new method for the construction of SI models based on the Monte Carlo approach. In the present study, the proposed method was tested by constructing the SI model for the polygon-mesh version of the ICRP reference male phantom currently under development. We believe that the new SI model is anatomically more realistic than the stylized SI models. Furthermore, our simulation results show that the new SI model, for both external and internal photon exposures, leads to dose values that are more similar to those of the original ICRP male voxel phantom than does the previously constructed stylized SI model.
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Affiliation(s)
- Yeon Soo Yeom
- Department of Nuclear Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 133-791, Korea
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Bonfrate A, Farah J, De Marzi L, Delacroix S, Hérault J, Sayah R, Lee C, Bolch WE, Clairand I. Influence of beam incidence and irradiation parameters on stray neutron doses to healthy organs of pediatric patients treated for an intracranial tumor with passive scattering proton therapy. Phys Med 2016; 32:590-9. [PMID: 27050170 DOI: 10.1016/j.ejmp.2016.03.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Revised: 02/05/2016] [Accepted: 03/14/2016] [Indexed: 11/28/2022] Open
Abstract
PURPOSE In scattering proton therapy, the beam incidence, i.e. the patient's orientation with respect to the beam axis, can significantly influence stray neutron doses although it is almost not documented in the literature. METHODS MCNPX calculations were carried out to estimate stray neutron doses to 25 healthy organs of a 10-year-old female phantom treated for an intracranial tumor. Two beam incidences were considered in this article, namely a superior (SUP) field and a right lateral (RLAT) field. For both fields, a parametric study was performed varying proton beam energy, modulation width, collimator aperture and thickness, compensator thickness and air gap size. RESULTS Using a standard beam line configuration for a craniopharyngioma treatment, neutron absorbed doses per therapeutic dose of 63μGyGy(-1) and 149μGyGy(-1) were found at the heart for the SUP and the RLAT fields, respectively. This dose discrepancy was explained by the different patient's orientations leading to changes in the distance between organs and the final collimator where external neutrons are mainly produced. Moreover, investigations on neutron spectral fluence at the heart showed that the number of neutrons was 2.5times higher for the RLAT field compared against the SUP field. Finally, the influence of some irradiation parameters on neutron doses was found to be different according to the beam incidence. CONCLUSION Beam incidence was thus found to induce large variations in stray neutron doses, proving that this parameter could be optimized to enhance the radiation protection of the patient.
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Affiliation(s)
- A Bonfrate
- IRSN - Institut de Radioprotection et de Sûreté Nucléaire, Service de Dosimétrie Externe BP17, 92262 Fontenay-aux-Roses Cedex, France.
| | - J Farah
- IRSN - Institut de Radioprotection et de Sûreté Nucléaire, Service de Dosimétrie Externe BP17, 92262 Fontenay-aux-Roses Cedex, France.
| | - L De Marzi
- Institut Curie - Centre de Protonthérapie d'Orsay (CPO) - Campus universitaire bâtiment 101, 91898 Orsay, France
| | - S Delacroix
- Institut Curie - Centre de Protonthérapie d'Orsay (CPO) - Campus universitaire bâtiment 101, 91898 Orsay, France
| | - J Hérault
- Centre Antoine Lacassagne (CAL) - Cyclotron biomédical, 227 avenue de la Lanterne, 06200 Nice, France
| | - R Sayah
- IRSN - Institut de Radioprotection et de Sûreté Nucléaire, Service de Dosimétrie Externe BP17, 92262 Fontenay-aux-Roses Cedex, France
| | - C Lee
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institute of Health, Rockville, MD 20850, USA
| | - W E Bolch
- J Crayton Pruitt Family Departments of Biomedical Engineering, University of Florida, Gainesville, FL 32611, USA
| | - I Clairand
- IRSN - Institut de Radioprotection et de Sûreté Nucléaire, Service de Dosimétrie Externe BP17, 92262 Fontenay-aux-Roses Cedex, France
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Matsumoto S, Koba Y, Kohno R, Lee C, Bolch WE, Kai M. Secondary Neutron Doses to Pediatric Patients During Intracranial Proton Therapy: Monte Carlo Simulation of the Neutron Energy Spectrum and its Organ Doses. HEALTH PHYSICS 2016; 110:380-386. [PMID: 26910030 DOI: 10.1097/hp.0000000000000461] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Proton therapy has the physical advantage of a Bragg peak that can provide a better dose distribution than conventional x-ray therapy. However, radiation exposure of normal tissues cannot be ignored because it is likely to increase the risk of secondary cancer. Evaluating secondary neutrons generated by the interaction of the proton beam with the treatment beam-line structure is necessary; thus, performing the optimization of radiation protection in proton therapy is required. In this research, the organ dose and energy spectrum were calculated from secondary neutrons using Monte Carlo simulations. The Monte Carlo code known as the Particle and Heavy Ion Transport code System (PHITS) was used to simulate the transport proton and its interaction with the treatment beam-line structure that modeled the double scattering body of the treatment nozzle at the National Cancer Center Hospital East. The doses of the organs in a hybrid computational phantom simulating a 5-y-old boy were calculated. In general, secondary neutron doses were found to decrease with increasing distance to the treatment field. Secondary neutron energy spectra were characterized by incident neutrons with three energy peaks: 1×10, 1, and 100 MeV. A block collimator and a patient collimator contributed significantly to organ doses. In particular, the secondary neutrons from the patient collimator were 30 times higher than those from the first scatter. These results suggested that proactive protection will be required in the design of the treatment beam-line structures and that organ doses from secondary neutrons may be able to be reduced.
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Affiliation(s)
- Shinnosuke Matsumoto
- *Graduate school, Oita University of Nursing and Health Sciences. Oita city, Oita 870-1201, Japan; †Medical Exposure Research Project, National Institute of Radiological Sciences. Chiba city, Chiba 263-8555, Japan; ‡Division of Particle Therapy, National Cancer Center Hospital East. Kashiwa city, Chiba 277-8577, Japan; §Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institute of Health, Rockville, MD 20850, USA; **Department of Radiology, University of Florida, Gainesville, FL 32611, USA
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Dahdouh S, Varsier N, Nunez Ochoa MA, Wiart J, Peyman A, Bloch I. Infants and young children modeling method for numerical dosimetry studies: application to plane wave exposure. Phys Med Biol 2016; 61:1500-14. [PMID: 26815765 DOI: 10.1088/0031-9155/61/4/1500] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Numerical dosimetry studies require the development of accurate numerical 3D models of the human body. This paper proposes a novel method for building 3D heterogeneous young children models combining results obtained from a semi-automatic multi-organ segmentation algorithm and an anatomy deformation method. The data consist of 3D magnetic resonance images, which are first segmented to obtain a set of initial tissues. A deformation procedure guided by the segmentation results is then developed in order to obtain five young children models ranging from the age of 5 to 37 months. By constraining the deformation of an older child model toward a younger one using segmentation results, we assure the anatomical realism of the models. Using the proposed framework, five models, containing thirteen tissues, are built. Three of these models are used in a prospective dosimetry study to analyze young child exposure to radiofrequency electromagnetic fields. The results lean to show the existence of a relationship between age and whole body exposure. The results also highlight the necessity to specifically study and develop measurements of child tissues dielectric properties.
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Affiliation(s)
- S Dahdouh
- LTCI, CNRS, Télécom ParisTech, Université Paris Saclay, Paris, France. Whist Lab, Paris, France
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Chen Y, Qiu R, Li C, Wu Z, Li J. Construction of Chinese adult male phantom library and its application in the virtual calibration ofin vivomeasurement. Phys Med Biol 2016; 61:2124-44. [DOI: 10.1088/0031-9155/61/5/2124] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Patient-specific dosimetry using pretherapy [¹²⁴I]m-iodobenzylguanidine ([¹²⁴I]mIBG) dynamic PET/CT imaging before [¹³¹I]mIBG targeted radionuclide therapy for neuroblastoma. Mol Imaging Biol 2015; 17:284-94. [PMID: 25145966 DOI: 10.1007/s11307-014-0783-7] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
PURPOSE Iodine-131-m-iodobenzylguanidine ([(131)I]mIBG)-targeted radionuclide therapy (TRT) is a standard treatment for recurrent or refractory neuroblastoma with response rates of 30-40 %. The aim of this study is to demonstrate patient-specific dosimetry using quantitative [(124)I]mIBG positron emission tomography/X-ray computed tomography (PET/CT) imaging with a GEometry ANd Tracking 4 (Geant4)-based Monte Carlo method for better treatment planning. PROCEDURES A Monte Carlo dosimetry method was developed using the Geant4 toolkit with voxelized anatomical geometry and source distribution as input. The presegmented hybrid computational human phantoms developed by the University of Florida and the National Cancer Institute (UF/NCI) were used as a surrogate to characterize the anatomy of a given patient. S values for I-131 were estimated by the phantoms coupled with Geant4 and compared with those estimated by OLINDA|EXM and MCNPX for the newborn model. To obtain patient-specific biodistribution of [(131)I]mIBG, a 10-year-old girl with relapsed neuroblastoma was imaged with [(124)I]mIBG PET/CT at four time points prior to the planned [(131)I]mIBG TRT. The organ- and tumor-absorbed doses of the clinical case were estimated with the Geant4 method using the modified UF/NCI 10-year-old phantom with tumors and the patient-specific residence time. RESULTS For the newborn model, the Geant4 S values were consistent with the MCNPX S values. The S value ratio of the Geant4 method to OLINDA|EXM ranged from 0.08 to 6.5 of all major organs. The [(131)I]mIBG residence time quantified from the pretherapy [(124)I]mIBG PET/CT imaging of the 10-year-old patient was mostly comparable to those previously reported. Organ-absorbed dose for the salivary glands was 98.0 Gy, heart wall 36.5 Gy, and liver 34.3 Gy, while tumor-absorbed dose ranged from 143.9 to 1,641.3 Gy in different sites. CONCLUSIONS Patient-specific dosimetry for [(131)I]mIBG TRT was accomplished using pretherapy [(124)I]mIBG PET/CT imaging and a Geant4-based Monte Carlo dosimetry method. The Geant4 method with quantitative pretherapy imaging can provide dose estimates to normal organs and tumors with more realistic simulation geometry, and thus may improve treatment planning for [(131)I]mIBG TRT.
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Nguyen TT, Yeom YS, Kim HS, Wang ZJ, Han MC, Kim CH, Lee JK, Zankl M, Petoussi-Henss N, Bolch WE, Lee C, Chung BS. Incorporation of detailed eye model into polygon-mesh versions of ICRP-110 reference phantoms. Phys Med Biol 2015; 60:8695-707. [DOI: 10.1088/0031-9155/60/22/8695] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Yu D, Wang M, Liu Q. Development of Chinese reference man deformable surface phantom and its application to the influence of physique on electromagnetic dosimetry. Phys Med Biol 2015; 60:6833-46. [PMID: 26301501 DOI: 10.1088/0031-9155/60/17/6833] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A reference man is a theoretical individual that represents the average anatomical structure and physiological and metabolic features of a specific group of people and has been widely used in radiation safety research. With the help of an advantage in deformation, the present work proposed a Chinese reference man adult-male polygon-mesh surface phantom based on the Visible Chinese Human segment image dataset by surface rendering and deforming. To investigate the influence of physique on electromagnetic dosimetry in humans, a series of human phantoms with 10th, 50th and 90th body mass index and body circumference percentile physiques for Chinese adult males were further constructed by deforming the Chinese reference man surface phantom. All the surface phantoms were then voxelized to perform electromagnetic field simulation in a frequency range of 20 MHz to 3 GHz using the finite-difference time-domain method and evaluate the whole-body average and organ average specific absorption rate and the ratios of absorbed energy in skin, fat and muscle to the whole body. The results indicate thinner physique leads to higher WBSAR and the volume of subcutaneous fat, the penetration depth of the electromagnetic field in tissues and standing-wave occurrence may be the influence factors of physique on electromagnetic dosimetry.
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Affiliation(s)
- D Yu
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, 430074, People's Republic of China. MoE Key Laboratory for Biomedical Photonics, Department of Biomedical Engineering, Huazhong University of Science and Technology, Wuhan, 430074, People's Republic of China
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Takahashi F, Sato K, Endo A, Ono K, Ban N, Hasegawa T, Katsunuma Y, Yoshitake T, Kai M. Numerical Analysis of Organ Doses Delivered During Computed Tomography Examinations Using Japanese Adult Phantoms with the WAZA-ARI Dosimetry System. HEALTH PHYSICS 2015; 109:104-112. [PMID: 26107430 DOI: 10.1097/hp.0000000000000299] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A dosimetry system for computed tomography (CT) examinations, named WAZA-ARI, is being developed to accurately assess radiation doses to patients in Japan. For dose calculations in WAZA-ARI, organ doses were numerically analyzed using average adult Japanese male (JM) and female (JF) phantoms with the Particle and Heavy Ion Transport code System (PHITS). Experimental studies clarified the photon energy distribution of emitted photons and dose profiles on the table for some multi-detector row CT (MDCT) devices. Numerical analyses using a source model in PHITS could specifically take into account emissions of x rays from the tube to the table with attenuation of photons through a beam-shaping filter for each MDCT device based on the experiment results. The source model was validated by measuring the CT dose index (CTDI). Numerical analyses with PHITS revealed a concordance of organ doses with body sizes of the JM and JF phantoms. The organ doses in the JM phantoms were compared with data obtained using previously developed systems. In addition, the dose calculations in WAZA-ARI were verified with previously reported results by realistic NUBAS phantoms and radiation dose measurement using a physical Japanese model (THRA1 phantom). The results imply that numerical analyses using the Japanese phantoms and specified source models can give reasonable estimates of dose for MDCT devices for typical Japanese adults.
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Affiliation(s)
- Fumiaki Takahashi
- *Japan Atomic Energy Agency, †Tokyo Healthcare University, ‡Tokai University Oiso Hospital, §Tokai University Hospital, **Shin-Beppu Hospital, ††Oita University of Nursing and Health Sciences
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Xie T, Lee C, Bolch WE, Zaidi H. Assessment of radiation dose in nuclear cardiovascular imaging using realistic computational models. Med Phys 2015; 42:2955-66. [PMID: 26127049 PMCID: PMC5148206 DOI: 10.1118/1.4921364] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Revised: 04/24/2015] [Accepted: 05/08/2015] [Indexed: 12/26/2022] Open
Abstract
PURPOSE Nuclear cardiology plays an important role in clinical assessment and has enormous impact on the management of a variety of cardiovascular diseases. Pediatric patients at different age groups are exposed to a spectrum of radiation dose levels and associated cancer risks different from those of adults in diagnostic nuclear medicine procedures. Therefore, comprehensive radiation dosimetry evaluations for commonly used myocardial perfusion imaging (MPI) and viability radiotracers in target population (children and adults) at different age groups are highly desired. METHODS Using Monte Carlo calculations and biological effects of ionizing radiation VII model, we calculate the S-values for a number of radionuclides (Tl-201, Tc-99m, I-123, C-11, N-13, O-15, F-18, and Rb-82) and estimate the absorbed dose and effective dose for 12 MPI radiotracers in computational models including the newborn, 1-, 5-, 10-, 15-yr-old, and adult male and female computational phantoms. RESULTS For most organs, (201)Tl produces the highest absorbed dose whereas (82)Rb and (15)O-water produce the lowest absorbed dose. For the newborn baby and adult patient, the effective dose of (82)Rb is 48% and 77% lower than that of (99m)Tc-tetrofosmin (rest), respectively. CONCLUSIONS (82)Rb results in lower effective dose in adults compared to (99m)Tc-labeled tracers. However, this advantage is less apparent in children. The produced dosimetric databases for various radiotracers used in cardiovascular imaging, using new generation of computational models, can be used for risk-benefit assessment of a spectrum of patient population in clinical nuclear cardiology practice.
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Affiliation(s)
- Tianwu Xie
- Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, Geneva 4 CH-1211, Switzerland
| | - Choonsik Lee
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institute of Health, Bethesda, Maryland 20852
| | - Wesley E Bolch
- Departments of Nuclear & Radiological and Biomedical Engineering, University of Florida, Gainesville, Florida 32611
| | - Habib Zaidi
- Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, Geneva 4 CH-1211, Switzerland; Geneva Neuroscience Center, Geneva University, Geneva CH-1205, Switzerland; and Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen 9700 RB, Netherlands
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Satoh D, Furuta T, Takahashi F, Endo A, Lee C, Bolch WE. Age-dependent dose conversion coefficients for external exposure to radioactive cesium in soil. J NUCL SCI TECHNOL 2015. [DOI: 10.1080/00223131.2015.1021286] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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49
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Dong L, Li T, Liu C. Construction of hybrid Chinese reference adult phantoms and estimation of dose conversion coefficients for muons. RADIATION PROTECTION DOSIMETRY 2015; 164:219-227. [PMID: 25313173 DOI: 10.1093/rpd/ncu300] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Accepted: 09/06/2014] [Indexed: 06/04/2023]
Abstract
A set of fluence-to-effective dose conversion coefficients of external exposure to muons were investigated for Chinese hybrid phantom references, which include both male and female. Both polygon meshes and Non-Uniform Rational B-Spline (NURBS) surfaces were used to descried the boundary of the organs and tissues in these phantoms. The 3D-DOCTOR and Rhinoceros software were used to polygonise the colour slice images and generate the NURBS surfaces, respectively. The voxelisation is completed using the BINVOX software and the assembly finished by using MATLAB codes. The voxel resolutions were selected to be 0.22 × 0.22 × 0.22 cm(3) and 0.2 × 0.2 × 0.2 cm(3) for male and female phantoms, respectively. All parts of the final phantoms were matched to their reference organ masses within a tolerance of ±5%. The conversion coefficients for negative and positive muons were calculated with the FLUKA transport code. There were 21 external monoenergetic beams ranging from 0.01 GeV to 100 TeV in 5 different geometrical conditions of irradiation.
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Affiliation(s)
- Liang Dong
- Fundamental Science on Nuclear Safety and Simulation Technology Laboratory, College of Nuclear Science and Technology, Harbin Engineering University, Harbin 150001, China
| | - Taosheng Li
- Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, Hefei, Anhui 230031, China
| | - Chunyu Liu
- Fundamental Science on Nuclear Safety and Simulation Technology Laboratory, College of Nuclear Science and Technology, Harbin Engineering University, Harbin 150001, China
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Ma AK, Hussein MA, Altaher KM, Farid KY, Amer M, Aldhafery BF, Alghamdi AA. Fluence-to-effective dose conversion coefficients from a Saudi population based phantom for monoenergetic photon beams from 10 keV to 20 MeV. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2015; 35:75-86. [PMID: 25517542 DOI: 10.1088/0952-4746/35/1/75] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Fluence-to-dose conversion coefficients are important quantities for radiation protection, derived from Monte Carlo simulations of the radiation particles through a stylised phantom or voxel based phantoms. The voxel phantoms have been developed for many ethnic groups for their accurate reflection of the anatomy. In this study, we used the Monte Carlo code MCNPX to calculate the photon fluence-to-effective dose conversion coefficients with a voxel phantom based on the Saudi Arabian male population. Six irradiation geometries, anterior-posterior (AP), posterior-anterior (PA), left lateral (LLAT), right lateral (RLAT), rotational (ROT) and isotropic (ISO) were simulated for monoenergetic photon beams from 10 keV to 20 MeV. We compared the coefficients with the reference values in ICRP Publication 116. The coefficients in the AP and PA geometries match the reference values to 9% and 12% on average as measured by root mean square while those in the LLAT, RLAT ROT and ISO geometries differ, mostly below, from the reference by 23, 22, 15 and 16%, respectively. The torso of the Saudi phantom is wider than the ICRP reference male phantom and likely to cause more attenuation to the lateral beam. The ICRP reference coefficients serve well for the Saudi male population as conservative estimations for the purpose of radiation protection.
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Affiliation(s)
- Andy K Ma
- Department of Radiological Sciences, University of Dammam, Dammam, Saudi Arabia
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