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De Benetti F, Brosch-Lenz J, Guerra González JM, Uribe C, Eiber M, Navab N, Wendler T. DosePatch: physics-inspired cropping layout for patch-based Monte Carlo simulations to provide fast and accurate internal dosimetry. EJNMMI Phys 2024; 11:51. [PMID: 38922372 DOI: 10.1186/s40658-024-00646-y] [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: 06/12/2023] [Accepted: 05/08/2024] [Indexed: 06/27/2024] Open
Abstract
BACKGROUND Dosimetry-based personalized therapy was shown to have clinical benefits e.g. in liver selective internal radiation therapy (SIRT). Yet, there is no consensus about its introduction into clinical practice, mainly as Monte Carlo simulations (gold standard for dosimetry) involve massive computation time. We addressed the problem of computation time and tested a patch-based approach for Monte Carlo simulations for internal dosimetry to improve parallelization. We introduce a physics-inspired cropping layout for patch-based MC dosimetry, and compare it to cropping layouts of the literature as well as dosimetry using organ-S-values, and dose kernels, taking whole-body Monte Carlo simulations as ground truth. This was evaluated in five patients receiving Yttrium-90 liver SIRT. RESULTS The patch-based Monte Carlo approach yielded the closest results to the ground truth, making it a valid alternative to the conventional approach. Our physics-inspired cropping layout and mosaicking scheme yielded a voxel-wise error of < 2% compared to whole-body Monte Carlo in soft tissue, while requiring only ≈ 10% of the time. CONCLUSIONS This work demonstrates the feasibility and accuracy of physics-inspired cropping layouts for patch-based Monte Carlo simulations.
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Affiliation(s)
- Francesca De Benetti
- Chair for Computer Aided Medical Procedures and Augmented Reality, Technical University of Munich, Garching, Germany
| | - Julia Brosch-Lenz
- Department of Nuclear Medicine, Klinikum Rechts der Isar, Technical University of Munich, Munich, Germany
| | - Jorge Mario Guerra González
- Chair for Computer Aided Medical Procedures and Augmented Reality, Technical University of Munich, Garching, Germany
| | - Carlos Uribe
- Department of Integrative Oncology, BC Cancer Research Institute, Vancouver, Canada
| | - Matthias Eiber
- Department of Nuclear Medicine, Klinikum Rechts der Isar, Technical University of Munich, Munich, Germany
| | - Nassir Navab
- Chair for Computer Aided Medical Procedures and Augmented Reality, Technical University of Munich, Garching, Germany
| | - Thomas Wendler
- Chair for Computer Aided Medical Procedures and Augmented Reality, Technical University of Munich, Garching, Germany.
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Augsburg, Augsburg, Germany.
- Institute of Digital Medicine, University Hospital Augsburg, Neusaess, Germany.
- Clinical Computational Medical Imaging Research, University of Augsburg, Augsburg, Germany.
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Talebi AS, Bodaghi R, Bagherzadeh S. Lifetime attributable risks (LARs) of cancer in the fetus associated with maternal radiography examinations. Int J Radiat Biol 2024; 100:420-426. [PMID: 38193807 DOI: 10.1080/09553002.2023.2295294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 10/14/2023] [Indexed: 01/10/2024]
Abstract
PURPOSE For various reasons, pregnant women are occasionally exposed to ionizing radiation during radiology examinations. In these situations, it is essential to determine the radiation dose to the fetus and any associated risks. The present study attempts to calculate the mean dose for the fetus to estimate the possible cancer induction and cancer mortality risks resulting from maternal radiography exams. MATERIAL AND METHODS The GATE Monte Carlo platform and a standard voxelized pregnant phantom were employed to calculate fetal radiation dose during maternal radiography exams. The data published in Biological Effects of Ionizing Radiation VII were used to convert fetal dose to lifetime attributable risks (LARs) of cancer incidence and cancer-related mortality. RESULTS The fetal doses and LARs of cancer incidence and cancer-related mortality for the radiographs of the chest and skull were negligible. The maximum LAR values for the lateral view of the abdomen in computed and digital radiography are 5598.29 and 2238.95 per 100,000 individuals, respectively. The computed radiography of the lateral view of the abdomen revealed the highest LAR of cancer-related mortality (2074.30 deaths for every 100,000 people). CONCLUSION The radiation dose incurred by the fetus due to chest and skull radiographs was minimal and unlikely to cause any abnormalities in the fetus. The discernible elevation in the lifetime attributable risk associated with cancer incidence and mortality arising from lateral computed radiography examinations of the abdomen warrants careful consideration within the realm of maternal radiography examinations.
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Affiliation(s)
- Asra Sadat Talebi
- Department of Medical Physics, Tarbiat Modares University, Tehran, Iran
| | - Roghiyeh Bodaghi
- Department of Medical Physics, Tarbiat Modares University, Tehran, Iran
| | - Saeed Bagherzadeh
- Department of Medical Physics, Tarbiat Modares University, Tehran, Iran
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Koniar H, Miller C, Rahmim A, Schaffer P, Uribe C. A GATE simulation study for dosimetry in cancer cell and micrometastasis from the 225Ac decay chain. EJNMMI Phys 2023; 10:46. [PMID: 37525027 PMCID: PMC10390455 DOI: 10.1186/s40658-023-00564-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Accepted: 07/24/2023] [Indexed: 08/02/2023] Open
Abstract
BACKGROUND Radiopharmaceutical therapy (RPT) with alpha-emitting radionuclides has shown great promise in treating metastatic cancers. The successive emission of four alpha particles in the 225Ac decay chain leads to highly targeted and effective cancer cell death. Quantifying cellular dosimetry for 225Ac RPT is essential for predicting cell survival and therapeutic success. However, the leading assumption that all 225Ac progeny remain localized at their target sites likely overestimates the absorbed dose to cancer cells. To address limitations in existing semi-analytic approaches, this work evaluates S-values for 225Ac's progeny radionuclides with GATE Monte Carlo simulations. METHODS The cellular geometries considered were an individual cell (10 µm diameter with a nucleus of 8 µm diameter) and a cluster of cells (micrometastasis) with radionuclides localized in four subcellular regions: cell membrane, cytoplasm, nucleus, or whole cell. The absorbed dose to the cell nucleus was scored, and self- and cross-dose S-values were derived. We also evaluated the total absorbed dose with various degrees of radiopharmaceutical internalization and retention of the progeny radionuclides 221Fr (t1/2 = 4.80 m) and 213Bi (t1/2 = 45.6 m). RESULTS For the cumulative 225Ac decay chain, our self- and cross-dose nuclear S-values were both in good agreement with S-values published by MIRDcell, with per cent differences ranging from - 2.7 to - 8.7% for the various radionuclide source locations. Source location had greater effects on self-dose S-values than the intercellular cross-dose S-values. Cumulative 225Ac decay chain self-dose S-values increased from 0.167 to 0.364 GyBq-1 s-1 with radionuclide internalization from the cell surface into the cell. When progeny migration from the target site was modelled, the cumulative self-dose S-values to the cell nucleus decreased by up to 71% and 21% for 221Fr and 213Bi retention, respectively. CONCLUSIONS Our GATE Monte Carlo simulations resulted in cellular S-values in agreement with existing MIRD S-values for the alpha-emitting radionuclides in the 225Ac decay chain. To obtain accurate absorbed dose estimates in 225Ac studies, accurate understanding of daughter migration is critical for optimized injected activities. Future work will investigate other novel preclinical alpha-emitting radionuclides to evaluate therapeutic potency and explore realistic cellular geometries corresponding to targeted cancer cell lines.
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Affiliation(s)
- Helena Koniar
- Life Sciences Division, TRIUMF, Vancouver, BC, Canada.
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada.
| | - Cassandra Miller
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada
- Department of Integrative Oncology, BC Cancer Research Institute, Vancouver, BC, Canada
| | - Arman Rahmim
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada
- Department of Integrative Oncology, BC Cancer Research Institute, Vancouver, BC, Canada
- Department of Radiology, University of British Columbia, Vancouver, BC, Canada
| | - Paul Schaffer
- Life Sciences Division, TRIUMF, Vancouver, BC, Canada
- Department of Radiology, University of British Columbia, Vancouver, BC, Canada
- Department of Chemistry, Simon Fraser University, Burnaby, BC, Canada
| | - Carlos Uribe
- Department of Radiology, University of British Columbia, Vancouver, BC, Canada
- Functional Imaging, BC Cancer, Vancouver, BC, Canada
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Kesner AL, Carter LM, Ramos JCO, Lafontaine D, Olguin EA, Brown JL, President B, Jokisch DW, Fisher DR, Bolch WE. MIRD Pamphlet No. 28, Part 1: MIRDcalc-A Software Tool for Medical Internal Radiation Dosimetry. J Nucl Med 2023; 64:1117-1124. [PMID: 37268428 PMCID: PMC10315701 DOI: 10.2967/jnumed.122.264225] [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: 04/04/2022] [Revised: 03/21/2023] [Indexed: 06/04/2023] Open
Abstract
Medical internal radiation dosimetry constitutes a fundamental aspect of diagnosis, treatment, optimization, and safety in nuclear medicine. The MIRD committee of the Society of Nuclear Medicine and Medical Imaging developed a new computational tool to support organ-level and suborgan tissue dosimetry (MIRDcalc, version 1). Based on a standard Excel spreadsheet platform, MIRDcalc provides enhanced capabilities to facilitate radiopharmaceutical internal dosimetry. This new computational tool implements the well-established MIRD schema for internal dosimetry. The spreadsheet incorporates a significantly enhanced database comprising details for 333 radionuclides, 12 phantom reference models (International Commission on Radiological Protection), 81 source regions, and 48 target regions, along with the ability to interpolate between models for patient-specific dosimetry. The software also includes sphere models of various composition for tumor dosimetry. MIRDcalc offers several noteworthy features for organ-level dosimetry, including modeling of blood source regions and dynamic source regions defined by user input, integration of tumor tissues, error propagation, quality control checks, batch processing, and report-preparation capabilities. MIRDcalc implements an immediate, easy-to-use single-screen interface. The MIRDcalc software is available for free download (www.mirdsoft.org) and has been approved by the Society of Nuclear Medicine and Molecular Imaging.
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Affiliation(s)
- Adam L Kesner
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York;
| | - Lukas M Carter
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Juan C Ocampo Ramos
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Daniel Lafontaine
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Edmond A Olguin
- Beth Israel Deaconess Medical Center, Department of Radiology, Harvard Medical School, Boston, Massachusetts
| | - Justin L Brown
- J. Crayton Pruitt Department of Biomedical Engineering, University of Florida, Gainesville, Florida
| | - Bonnie President
- J. Crayton Pruitt Department of Biomedical Engineering, University of Florida, Gainesville, Florida
| | - Derek W Jokisch
- Department of Physics and Engineering, Francis Marion University, Florence, South Carolina
- Center for Radiation Protection Knowledge, Oak Ridge National Laboratory, Oak Ridge, Tennessee; and
| | - Darrell R Fisher
- University of Washington and Versant Medical Physics and Radiation Safety, Richland, Washington
| | - Wesley E Bolch
- J. Crayton Pruitt Department of Biomedical Engineering, University of Florida, Gainesville, Florida
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Coleman D, Griffin KT, Dewji SA. Stylized versus voxel phantoms: quantification of internal organ chord length distances. Phys Med Biol 2023; 68. [PMID: 36780697 DOI: 10.1088/1361-6560/acbbb6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Accepted: 02/13/2023] [Indexed: 02/15/2023]
Abstract
Dosimetric calculations, whether for radiation protection or nuclear medicine applications, are greatly influenced by the use of computational models of humans, called anthropomorphic phantoms. As anatomical models of phantoms have evolved and expanded, thus has the need for quantifying differences among each of these representations that yield variations in organ dose coefficients, whether from external radiation sources or internal emitters. This work represents an extension of previous efforts to quantify the differences in organ positioning within the body between a stylized and voxel phantom series. Where prior work focused on the organ depth distribution vis-à-vis the surface of the phantom models, the work described here quantifies the intra-organ and inter-organ distributions through calculation of the mean chord lengths. The revised Oak Ridge National Laboratory stylized phantom series and the University of Florida/National Cancer Institute voxel phantom series including a newborn, 1-, 5-, 10- and 15 year old, and adult phantoms were compared. Organ distances in the stylized phantoms were computed using a ray-tracing technique available through Monte Carlo radiation transport simulations in MCNP6. Organ distances in the voxel phantom were found using phantom matrix manipulation. Quantification of differences in organ chord lengths between the phantom series displayed that the organs of the stylized phantom series are typically situated farther away from one another than within the voxel phantom series. The impact of this work was to characterize the intra-organ and inter-organ distributions to explain the variations in updated internal dose coefficient quantities (i.e. specific absorbed fractions) while providing relevant data defining the spatial and volumetric organ distributions in the phantoms for use in subsequent internal dosimetric computations, with prospective relevance to patient-specific individualized dosimetry, as well as informing machine learning definition of organs using these reference models.
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Affiliation(s)
- D Coleman
- University of Wisconsin-Madison, Department of Medical Physics 1111 Highland Ave Rm 1005, Madison, WI 53705-2275, United States of America
| | - K T Griffin
- National Cancer Institute, Radiation Epidemiology Branch, 9609 Medical Center Drive MSC 9776, Bethesda, MD 20892-2590, United States of America.,Georgia Institute of Technology, Nuclear and Radiological Engineering and Medical Physics Programs, 770 State Street, Atlanta, GA 30332-0405, United States of America
| | - S A Dewji
- Georgia Institute of Technology, Nuclear and Radiological Engineering and Medical Physics Programs, 770 State Street, Atlanta, GA 30332-0405, United States of America
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Specific absorbed fractions of electrons and photons for Digimouse voxelized phantom using GATE/GEANT4 Monte-Carlo simulation. Appl Radiat Isot 2023; 193:110637. [PMID: 36630783 DOI: 10.1016/j.apradiso.2022.110637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 11/19/2022] [Accepted: 12/23/2022] [Indexed: 12/29/2022]
Abstract
Knowledge of SAF at different energies is crucial for internal dosimetry. For this purpose, a set of calculated SAF values for a mouse voxelized phantom's selected organs are presented below. Values of SAF were calculated for mono-energetic photons and electrons with energy varying from 10 keV to 4 MeV using the Monte Carlo simulation via GATE/GEANT4 code (GEANT4 Application for Emission Tomography). The heart, liver, lungs, kidneys, and spleen were considered as the source organs from which the particles were released. Then, the estimated results were compared to those calculated in a previous study using EGS4 code. It is indicated that the obtained results are in good agreement with the reference values for all energies of photons and electrons, with discrepancies less than 9% and 5% for self-irradiation and cross-irradiation, respectively.
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Borbinha J, Ferreira P, Costa D, Vaz P, Di Maria S. Targeted radionuclide therapy directed to the tumor phenotypes: A dosimetric approach using MC simulations. Appl Radiat Isot 2023; 192:110569. [PMID: 36436229 DOI: 10.1016/j.apradiso.2022.110569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 11/07/2022] [Accepted: 11/16/2022] [Indexed: 11/21/2022]
Abstract
BACKGROUND In Targeted Radionuclide Therapy (TRT), the continuous technological effort in imaging tumor phenotypes (i.e. sub-volumes with different phenotypic characteristics) and in precise radiopharmaceutical tumor-targeting, is allowing for a better dosimetric optimization at the tumor phenotype level. The aim of this study was to evaluate the dosimetric efficiency (considering strategic absorbed dose delivery to the phenotypes) of personalized TRT directed to the tumor phenotypes. METHODS The dosimetric assessment was performed using a four-phenotype realistic tumor model implemented within the ICRP reference voxel phantom and simulations using the state-of-the-art Monte Carlo program PENELOPE. The dose assessment was performed for five radionuclides commonly used in therapy and/or diagnostic procedures: 125I, 99mTc, 177Lu, 161Tb and 67Ga. Two irradiation scenarios were considered: (i) the Whole Tumor Treatment Planning Scenario (WTTPS), i.e. the four phenotypes irradiated with the same radionuclide; (ii) the Phenotype Treatment Planning Scenario (PTPS), i.e. each phenotype irradiated by a single radionuclide. The optimal radionuclide configurations were studied considering the maximization of the absorbed dose delivered to the tumor and the minimization of dose to healthy tissues. RESULTS In WTTPS, 125I outperforms the other radionuclides in terms of the ratio of the maximum absorbed dose delivered to the tumor and the minimum absorbed dose delivered to healthy tissues. In the PTPS, the use of 161Tb in combination with the other radionuclides maximizes the absorbed dose in the tumor tissues while simultaneously minimizing dose to healthy tissue, compared to the WTTPS. In agreement with recent pre-clinical studies, our computational results confirm and indicate the beneficial additive dosimetric effects of Auger and conversion electrons of 161Tb with respect to 177Lu, when considering the same cumulated activity for both. Interestingly, in considering a realistic tumor model, the better dosimetric performances of 161Tb were confirmed also for tumor volumes ranging from 1.98 cm3 to 33.32 cm3. CONCLUSIONS Dose assessment in realistic non-homogeneous tumor models could provide more insights with respect to consider only homogenous water-spheres tumor models and should be taken into account in dosimetry-based TRT planning studies.
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Affiliation(s)
- Jorge Borbinha
- Centro de Ciências e Tecnologias Nucleares - Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10, ao km 139,7, 2695-066, Bobadela, Portugal.
| | - Paulo Ferreira
- Champalimaud Centre for the Unknown, Fundação Champalimaud, Avenida Brasília, 1400-038, Lisboa, Portugal.
| | - Durval Costa
- Champalimaud Centre for the Unknown, Fundação Champalimaud, Avenida Brasília, 1400-038, Lisboa, Portugal.
| | - Pedro Vaz
- Centro de Ciências e Tecnologias Nucleares - Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10, ao km 139,7, 2695-066, Bobadela, Portugal.
| | - Salvatore Di Maria
- Centro de Ciências e Tecnologias Nucleares - Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10, ao km 139,7, 2695-066, Bobadela, Portugal.
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8
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Kayal G, Clayton N, Vergara-Gil A, Struelens L, Bardiès M. Proof-of-concept of DosiTest: A virtual multicentric clinical trial for assessing uncertainties in molecular radiotherapy dosimetry. Phys Med 2022; 97:25-35. [PMID: 35339863 DOI: 10.1016/j.ejmp.2022.03.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 01/19/2022] [Accepted: 03/14/2022] [Indexed: 11/16/2022] Open
Abstract
Clinical dosimetry in molecular radiotherapy (MRT) is a multi-step procedure, prone to uncertainties at every stage of the dosimetric workflow. These are difficult to assess, especially as some are complex or even impossible to measure experimentally. The DosiTest project was initiated to assess the variability associated with clinical dosimetry, by setting up a 'virtual' multicentric clinical dosimetry trial based on Monte Carlo (MC) modelling. A reference patient model with a realistic geometry and activity input for a specific tracer is considered. Reference absorbed dose rate distribution maps are generated at various time-points from MC modelling, combining precise information on density and activity distributions (voxel wise). Then, centre-specific calibration and patient SPECT/CT datasets are modelled, on which the clinical centres can perform clinical (i.e. image-based) dosimetry. The results of this dosimetric analysis can be benchmarked against the reference dosimetry to assess the variability induced by implementing different clinical dosimetry approaches. The feasibility of DosiTest is presented here for a clinical situation of therapeutic administration of 177Lu-DOTATATE (Lutathera®) peptide receptor radionuclide therapy (PRRT). From a real patient dataset composed of 5 SPECT/CT images and associated calibrations, we generated the reference absorbed dose rate images with GATE. Then, simulated SPECT/CT image generation based on GATE was performed, both for a calibration phantom and virtual patient images. Based on this simulated dataset, image-based dosimetry could be performed, and compared with reference dosimetry. The good agreement, between real and simulated images, and between reference and image-based dosimetry established the proof of concept of DosiTest.
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Affiliation(s)
- G Kayal
- CRCT, UMR 1037, INSERM, Université Toulouse III Paul Sabatier, Toulouse, France; SCK CEN, Belgian Nuclear Research Centre, Boeretang 200, Mol 2400, Belgium.
| | - N Clayton
- CRCT, UMR 1037, INSERM, Université Toulouse III Paul Sabatier, Toulouse, France
| | - A Vergara-Gil
- CRCT, UMR 1037, INSERM, Université Toulouse III Paul Sabatier, Toulouse, France
| | - L Struelens
- SCK CEN, Belgian Nuclear Research Centre, Boeretang 200, Mol 2400, Belgium
| | - M Bardiès
- ICM, Département de Médecine Nucléaire, Montpellier, France; IRCM, UMR 1194 INSERM, Université de Montpellier and ICM, Montpellier, France
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Toward three-dimensional patient-specific internal dosimetry using GATE Monte Carlo technique. Radiat Phys Chem Oxf Engl 1993 2022. [DOI: 10.1016/j.radphyschem.2022.110046] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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10
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Amato E, Gnesin S, Cicone F, Auditore L. Fundamentals of internal radiation dosimetry. Nucl Med Mol Imaging 2022. [DOI: 10.1016/b978-0-12-822960-6.00142-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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Auditore L, Pistone D, Amato E, Italiano A. Monte Carlo methods in nuclear medicine. Nucl Med Mol Imaging 2022. [DOI: 10.1016/b978-0-12-822960-6.00136-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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12
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Bertolet A, Wehrenberg-Klee E, Bobić M, Grassberger C, Perl J, Paganetti H, Schuemann J. Pre- and post-treatment image-based dosimetry in 90Y-microsphere radioembolization using the TOPAS Monte Carlo toolkit. Phys Med Biol 2021; 66:10.1088/1361-6560/ac43fd. [PMID: 34915451 PMCID: PMC8729171 DOI: 10.1088/1361-6560/ac43fd] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 12/16/2021] [Indexed: 12/31/2022]
Abstract
Objective. To evaluate the pre-treatment and post-treatment imaging-based dosimetry of patients treated with 90Y-microspheres, including accurate estimations of dose to tumor, healthy liver and lung. To do so, the Monte Carlo (MC) TOPAS platform is in this work extended towards its utilization in radionuclide therapy.Approach. Five patients treated at the Massachusetts General Hospital were selected for this study. All patients had data for both pre-treatment SPECT-CT imaging using 99mTc-MAA as a surrogate of the 90Y-microspheres treatment and SPECT-CT imaging immediately after the 90Y activity administration. Pre- and post-treatment doses were computed with TOPAS using the SPECT images to localize the source positions and the CT images to account for tissue inhomoegeneities. We compared our results with analytical calculations following the voxel-based MIRD scheme.Main results. TOPAS results largely agreed with the MIRD-based calculations in soft tissue regions: the average difference in mean dose to the liver was 0.14 Gy GBq-1(2.6%). However, dose distributions in the lung differed considerably: absolute differences in mean doses to the lung ranged from 1.2 to 6.3 Gy GBq-1and relative differences from 153% to 231%. We also found large differences in the intra-hepatic dose distributions between pre- and post-treatment imaging, but only limited differences in the pulmonary dose.Significance. Doses to lung were found to be higher using TOPAS with respect to analytical calculations which may significantly underestimate dose to the lung, suggesting the use of MC methods for 90Y dosimetry. According to our results, pre-treatment imaging may still be representative of dose to lung in these treatments.
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Affiliation(s)
- Alejandro Bertolet
- Department of Radiation Oncology, Massachusetts General Hospital
and Harvard Medical School, Boston, MA, USA
| | - Eric Wehrenberg-Klee
- Department of Radiology, Division of Interventional Radiology,
Massachusetts General Hospital, Boston, MA, USA
| | - Mislav Bobić
- Department of Radiation Oncology, Massachusetts General Hospital
and Harvard Medical School, Boston, MA, USA & Department of Physics, ETH
Zürich, Zürich, Switzerland
| | - Clemens Grassberger
- Department of Radiation Oncology, Massachusetts General Hospital
and Harvard Medical School, Boston, MA
| | - Joseph Perl
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Harald Paganetti
- Department of Radiation Oncology, Massachusetts General Hospital
and Harvard Medical School, Boston, MA, USA
| | - Jan Schuemann
- Department of Radiation Oncology, Massachusetts General Hospital
and Harvard Medical School, Boston, MA, USA
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Neira S, Guiu-Souto J, Pais P, Rodríguez Martínez de Llano S, Fernández C, Pubul V, Ruibal Á, Pombar M, Gago-Arias A, Pardo-Montero J. Quantification of internal dosimetry in PET patients II: Individualized Monte Carlo-based dosimetry for [18F]fluorocholine PET. Med Phys 2021; 48:5448-5458. [PMID: 34260065 PMCID: PMC9291792 DOI: 10.1002/mp.15090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 06/04/2021] [Accepted: 06/28/2021] [Indexed: 12/03/2022] Open
Abstract
Purpose To obtain individualized internal doses with a Monte Carlo (MC) method in patients undergoing diagnostic [18F]FCH‐PET studies and to compare such doses with the MIRD method calculations. Methods A patient cohort of 17 males were imaged after intravenous administration of a mean [18F]FCH activity of 244.3 MBq. The resulting PET/CT images were processed in order to generate individualized input source and geometry files for dose computation with the MC tool GATE. The resulting dose estimates were studied and compared to the MIRD method with two different computational phantoms. Mass correction of the S‐factors was applied when possible. Potential sources of uncertainty were closely examined: the effect of partial body images, urinary bladder emptying, and biokinetic modeling. Results Large differences in doses between our methodology and the MIRD method were found, generally in the range ±25%, and up to ±120% for some cases. The mass scaling showed improvements, especially for non‐walled and high‐uptake tissues. Simulations of the urinary bladder emptying showed negligible effects on doses to other organs, with the exception of the prostate. Dosimetry based on partial PET/CT images (excluding the legs) resulted in an overestimation of mean doses to bone, skin, and remaining tissues, and minor differences in other organs/tissues. Estimated uncertainties associated with the biokinetics of FCH introduce variations of cumulated activities in the range of ±10% in the high‐uptake organs. Conclusions The MC methodology allows for a higher degree of dosimetry individualization than the MIRD methodology, which in some cases leads to important differences in dose values. Dosimetry of FCH‐PET based on a single partial PET study seems viable due to the particular biokinetics of FCH, even though some correction factors may need to be applied to estimate mean skin/bone doses.
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Affiliation(s)
- Sara Neira
- Group of Medical Physics and Biomathematics, Instituto de Investigación Sanitaria de Santiago, Santiago de Compostela, Spain
| | - Jacobo Guiu-Souto
- Department of Medical Physics, Centro Oncolóxico de Galicia, A Coruña, Spain
| | - Paulino Pais
- Department of Nuclear Medicine, Centro Oncolóxico de Galicia, A Coruña, Spain
| | | | - Carlos Fernández
- Department of Medical Physics, Centro Oncolóxico de Galicia, A Coruña, Spain
| | - Virginia Pubul
- Department of Nuclear Medicine, Complexo Hospitalario Universitario de Santiago de Compostela, Santiago de Compostela, Spain
| | - Álvaro Ruibal
- Department of Nuclear Medicine, Complexo Hospitalario Universitario de Santiago de Compostela, Santiago de Compostela, Spain.,Group of Molecular Imaging and Oncology, Instituto de Investigación Sanitaria de Santiago, Santiago de Compostela, Spain.,Molecular Imaging Group, Department of Radiology, Faculty of Medicine, Universidade de Santiago de Compostela, Santiago de Compostela, Spain.,Fundación Tejerina, Madrid, Spain
| | - Miguel Pombar
- Group of Molecular Imaging and Oncology, Instituto de Investigación Sanitaria de Santiago, Santiago de Compostela, Spain.,Department of Medical Physics, Complexo Hospitalario Universitario de Santiago de Compostela, Santiago de Compostela, Spain
| | - Araceli Gago-Arias
- Group of Medical Physics and Biomathematics, Instituto de Investigación Sanitaria de Santiago, Santiago de Compostela, Spain.,Department of Medical Physics, Complexo Hospitalario Universitario de Santiago de Compostela, Santiago de Compostela, Spain.,Institute of Physics, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Juan Pardo-Montero
- Group of Medical Physics and Biomathematics, Instituto de Investigación Sanitaria de Santiago, Santiago de Compostela, Spain.,Department of Medical Physics, Complexo Hospitalario Universitario de Santiago de Compostela, Santiago de Compostela, Spain
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14
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Schwarz BC, Godwin WJ, Wayson MB, Dewji SA, Jokisch DW, Lee C, Bolch WE. Specific absorbed fractions for a revised series of the UF/NCI pediatric reference phantoms: internal photon sources. Phys Med Biol 2021; 66:035006. [PMID: 33142280 DOI: 10.1088/1361-6560/abc708] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Assessment of radiation absorbed dose to internal organs of the body from the intake of radionuclides, or in the medical setting through the injection of radiopharmaceuticals, is generally performed based upon reference biokinetic models or patient imaging data, respectively. Biokinetic models estimate the time course of activity localized to source organs. The time-integration of these organ activity profiles are then scaled by the radionuclide S-value, which defines the absorbed dose to a target tissue per nuclear transformation in various source tissues. S-values are computed using established nuclear decay information (particle energies and yields), and a parameter termed the specific absorbed fraction (SAF). The SAF is the ratio of the absorbed fraction-fraction of particle energy emitted in the source tissue that is deposited in the target tissue-and the target organ mass. While values of the SAF may be computed using patient-specific or individual-specific anatomic models, they have been more widely available through the use of computational reference phantoms. In this study, we report on an extensive series of photon SAFs computed in a revised series of the University of Florida and the National Cancer Institute pediatric reference phantoms which have been modified to conform to the specifications embodied in the ICRP reference adult phantoms of Publication 110 (e.g. organs modeled, organ ID numbers, blood contribution to elemental compositions). Following phantom anatomical revisions, photon radiation transport simulations were performed using MCNPX v2.7 in each of the ten phantoms of the series-male and female newborn, 1 year old, 5 year old, 10 year old, and 15 year old-for 60 different tissues serving as source and/or target regions. A total of 25 photon energies were considered from 10 keV to 10 MeV along a logarithm energy grid. Detailed analyses were conducted of the relative statistical errors in the Monte Carlo target tissue energy deposition tallies at low photon energies and over all energies for source-target combinations at large intra-organ separation distances. Based on these analyses, various data smoothing algorithms were employed, including multi-point weighted data smoothing, and log-log interpolation at low energies (1 keV and 5 keV) using limiting SAF values based upon target organ mass to bound the interpolation interval. The final dataset is provided in a series of ten electronic supplemental files in MS Excel format. The results of this study were further used as the basis for assessing the radiative component of internal electron source SAFs as described in our companion paper (Schwarz et al 2021) for this same pediatric phantom series.
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Affiliation(s)
- Bryan C Schwarz
- Department of Radiology, University of Florida, Gainesville, FL 32611, United States of America
| | - William J Godwin
- Department of Radiation Oncology, Medical University of South Carolina, Charleston, SC 29407, United States of America
| | - Michael B Wayson
- Baylor Scott & White Health, Dallas, TX 76051, United States of America
| | - Shaheen A Dewji
- Department of Nuclear Engineering, Texas A&M University, College Station, TX 77843, United States of America
| | - Derek W Jokisch
- Department of Physics and Engineering, Francis Marion University, Florence, SC 29502, United States of America.,Center for Radiation Protection Knowledge, Oak Ridge National Laboratory, Oak Ridge, TN 37830, United States of America
| | - Choonsik Lee
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD 20850, United States of America
| | - Wesley E Bolch
- J Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL 32611, United States of America
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15
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Dosimetric assessment in different tumour phenotypes with auger electron emitting radionuclides: 99mTc, 125I, 161Tb, and 177Lu. Radiat Phys Chem Oxf Engl 1993 2020. [DOI: 10.1016/j.radphyschem.2020.108763] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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16
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Frezza A, Joachim-Paquet C, Chauvin M, Després P. Validation of irtGPUMCD, a GPU-based Monte Carlo internal dosimetry framework for radionuclide therapy. Phys Med 2020; 73:95-104. [PMID: 32334403 DOI: 10.1016/j.ejmp.2020.04.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 04/07/2020] [Accepted: 04/12/2020] [Indexed: 11/28/2022] Open
Abstract
PURPOSE Monte Carlo (MC) simulations are highly desirable for dose treatment planning and evaluation in radiation oncology. This is true also in emerging nuclear medicine applications such as internal radiotherapy with radionuclides. The purpose of this study is the validation of irtGPUMCD, a GPU-based MC code for dose calculations in internal radiotherapy. METHODS The female and male phantoms of the International Commission on Radiological Protection (ICRP 110) were used as benchmarking geometries for this study focused on 177Lu and including 99mTc and 131I. Dose calculations were also conducted for a real patient. For phantoms, twelve anatomical structures were considered as target/source organs. The S-values were evaluated with irtGPUMCD simulations (108 photons), with gamma branching ratios of ICRP 107 publication. The 177Lu electrons S-values were calculated for source organs only, based on local deposition of dose in irtGPUMCD. The S-value relative difference between irtGPUMCD and IDAC-DOSE were evaluated for all targets/sources considered. A DVHs comparison with GATE was conducted. An exponential track length estimator was introduced in irtGPUMCD to increase computational efficiency. RESULTS The relative S-value differences between irtGPUMCD and IDAC-DOSE were <5% while this comparison with GATE was <1%. The DVHs dosimetric indices comparison between GATE and irtGPUMCD for the patient led to an excellent agreement (<2%). The time required for the simulation of 108 photons was 1.5 min for the female phantom, and one minute for the real patient (<1% uncertainty). These results are promising and let envision the use of irtGPUMCD for internal dosimetry in clinical applications.
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Affiliation(s)
- Andrea Frezza
- Department of Physics, Engineering Physics and Optics and Cancer Research Center, Université Laval, Quebec City, QC G1V 0A6, Canada
| | - Charles Joachim-Paquet
- Department of Physics, Engineering Physics and Optics and Cancer Research Center, Université Laval, Quebec City, QC G1V 0A6, Canada
| | - Maxime Chauvin
- CRCT, UMR 1037, Inserm, Université Toulouse III Paul Sabatier, Toulouse, France
| | - Philippe Després
- Department of Physics, Engineering Physics and Optics and Cancer Research Center, Université Laval, Quebec City, QC G1V 0A6, Canada; Department of Radiation Oncology and Research Center of CHU de Québec - Université Laval, Quebec City, QC G1R 2J6, Canada.
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17
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Li T, Zhu L, Lu Z, Song N, Lin KH, Mok GSP. BIGDOSE: software for 3D personalized targeted radionuclide therapy dosimetry. Quant Imaging Med Surg 2020; 10:160-170. [PMID: 31956539 DOI: 10.21037/qims.2019.10.09] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Background Advance 3D quantitative radionuclide imaging techniques boost the accuracy of targeted radionuclide therapy (TRT) dosimetry to voxel level. The goal of this work is to develop a comprehensive 3D dosimetric software, BIGDOSE, with new features of image registration and virtual CT for patient-specific dosimetry. Methods BIGDOSE includes a portable graphical user interface written in Python, integrating (I) input of sequential ECT/CT images; (II) segmentation; (III) non-rigid image registration; (IV) curve fitting and voxel-based integration; (V) dose conversion and (VI) 3D dose analysis. The accuracy of the software was evaluated using a simulation study with 9 XCAT phantoms. We simulated SPECT/CT acquisitions at 1, 12, 24, 72 and 144-hrs post In-111 Zevalin injection with inter-scans misalignments using an analytical projector for medium energy general purpose (MEGP) collimator, modeling attenuation, scatter and collimator-detector response. The SPECT data were reconstructed using quantitative OS-EM method. A CT organ-based registration was performed before the dose calculation. Organ absorbed doses for the corresponding Y-90 therapeutic agent were calculated on target organs and compared with those obtained from OLINDA/EXM, using dose measured from GATE as the gold standard. One patient with In-111 DTPAOC injection as well as two patients with Y-90 microsphere embolization were used to demonstrate the clinical effectiveness of our software. Results In the simulation, the organ dose errors of BIGDOSE were -9.59%±9.06%, -8.36±5.82%, -23.41%±6.67%, -6.05%±2.06% for liver, spleen, kidneys and lungs, while they were -25.72%±12.52%, -14.93%±10.91%, -28.63%±12.97% and -45.30%±5.84% for OLINDA/EXM. Cumulative dose volume histograms, dose maps and iso-dose contours provided 3D dose distribution information on the simulated and patient data. Conclusions BIGDOSE provides a one-stop platform for voxel-based dose estimation with enhanced functions. It is a promising tool to streamline the current clinical TRT dosimetric practice with high accuracy, incorporating 3D personalized imaging information for improved treatment outcome.
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Affiliation(s)
- Tiantian Li
- Biomedical Imaging Laboratory (BIG), Department of Electrical and Computer Engineering, University of Macau, Macau SAR, China
| | - Licheng Zhu
- Department of Computer Science, Faculty of Science and Technology, University of Macau, Macau SAR, China
| | - Zhonglin Lu
- Biomedical Imaging Laboratory (BIG), Department of Electrical and Computer Engineering, University of Macau, Macau SAR, China
| | - Na Song
- Department of Nuclear Medicine, Albert Einstein College of Medicine, Yeshiva University, Bronx, New York, USA
| | - Ko-Han Lin
- Department of Nuclear Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Greta S P Mok
- Biomedical Imaging Laboratory (BIG), Department of Electrical and Computer Engineering, University of Macau, Macau SAR, China.,Faculty of Health Sciences, Institute of Collaborative Innovation, University of Macau, Macau SAR, China.,Center for Cognitive and Brain Sciences, Institute of Collaborative Innovation, University of Macau, Macau SAR, China
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18
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A comparison between GATE and MCNPX for photon dose calculations in radiation protection using a male voxel phantom. Radiat Phys Chem Oxf Engl 1993 2019. [DOI: 10.1016/j.radphyschem.2018.12.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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19
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Price E, Robinson AP, Cullen DM, Tipping J, Calvert N, Hamilton D, Oldfield C, Page E, Pietras B, Smith A. Improving molecular radiotherapy dosimetry using anthropomorphic calibration. Phys Med 2019; 58:40-46. [PMID: 30824148 DOI: 10.1016/j.ejmp.2019.01.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 12/10/2018] [Accepted: 01/17/2019] [Indexed: 11/17/2022] Open
Abstract
The optimised delivery of Molecular Radiotherapy requires individualised calculation of absorbed dose to both targeted lesions and neighbouring healthy tissue. To achieve this, accurate quantification of the activity distribution in the patient by external detection is vital. METHODS This work extends specific anatomy-related calibration to true organ shapes. A set of patient-specific 3D printed organ inserts based on a diagnostic CT scan was produced, comprising the liver, spleen and both kidneys. The inserts were used to calculate patient-specific calibration factors for 177Lu. These calibration factors were compared with previously reported calibration factors for corresponding organ models based on the Cristy and Eckerman phantom series and for a comparably sized sphere. Monte Carlo calculations of the patient-specific radiation dose were performed for comparison with current clinical dosimetry methods for these data. RESULTS Patient-specific calibration factors are shown to be dependent on the volume, shape and position of the organ containing activity with a corresponding impact on the calculation of the dose to the patient. The impact of organ morphology on calculated dose is reduced when the dominant contributor to dose is beta particles. This is due to the small range of beta particles in tissue. Overestimations of recovered activity and hence dose of up to 135% are observed. CONCLUSION For accurate quantification to be performed calibration factors accounting for organ size, shape and position must be used. Such quantification is vital if accurate, patient-specific dosimetry is to be achieved.
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Affiliation(s)
- Emlyn Price
- Schuster Laboratory, School of Physics and Astronomy, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom; Christie Medical Physics and Engineering (CMPE), The Christie NHS Foundation Trust, Wilmslow Road, Manchester M20 4BX, United Kingdom.
| | - Andrew P Robinson
- Schuster Laboratory, School of Physics and Astronomy, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom; National Physical Laboratory, Hampton Road, Teddington, Middlesex TW11 0LW, United Kingdom
| | - David M Cullen
- Schuster Laboratory, School of Physics and Astronomy, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Jill Tipping
- Christie Medical Physics and Engineering (CMPE), The Christie NHS Foundation Trust, Wilmslow Road, Manchester M20 4BX, United Kingdom
| | - Nick Calvert
- Christie Medical Physics and Engineering (CMPE), The Christie NHS Foundation Trust, Wilmslow Road, Manchester M20 4BX, United Kingdom
| | - David Hamilton
- Christie Medical Physics and Engineering (CMPE), The Christie NHS Foundation Trust, Wilmslow Road, Manchester M20 4BX, United Kingdom
| | - Christopher Oldfield
- Schuster Laboratory, School of Physics and Astronomy, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Emma Page
- Christie Medical Physics and Engineering (CMPE), The Christie NHS Foundation Trust, Wilmslow Road, Manchester M20 4BX, United Kingdom; Schuster Laboratory, School of Physics and Astronomy, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Ben Pietras
- Schuster Laboratory, School of Physics and Astronomy, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Andrew Smith
- Schuster Laboratory, School of Physics and Astronomy, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
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20
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Carvalho SM, Costa APM, Ramos CD, Castelo JHM, Brunetto SQ, Bonifácio DAB. Influence of the SPECT calibration source position on the absorbed dose calculation for 131I-NaI therapy using GATE simulations. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2018; 38:1284-1292. [PMID: 30019693 DOI: 10.1088/1361-6498/aad42a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Many research groups have studied nuclear medicine image quantification to improve its accuracy in dose estimation. This work aims to evaluate the influence of the source calibration position for absorbed dose calculation for a 131I-NaI therapy using Monte Carlo (MC) simulations. The calibration approach consisted of a cylindrical phantom filled with water. A cylindrical 131I source with 361.1 ± 3.6 kBq ml-1 was positioned at the center of the phantom and its outer part. Images were acquired with 150 00 counts per projection image acquired with SPECT detector (high counts density-HCD) and 3000 counts per projection (low counts density-LCD). MC simulations, performed with GATE code, were validated by comparing the S values of a water sphere uniformly filled with 131I, as from the sphere model of OLINDA/EXM 1.1. Calibration factors deviation between central and peripheral calibrations is more significant for HCD (18.3%) than for LCD images (3.7%). The 3D dose distribution map obtained from GATE resulted in a dose factor equal to 1.5 × 10-3 mGy/(MBq.s). For both HCD and LCD images, the commonly used approach, which employs the central source calibration to obtain the dose from a peripheral source, resulted in dose overestimation. Results suggest that organ dose calculation can be improved considering the organ position in the field of view. Finally, patients' radiation protection in dosimetry studies could be improved considering the calibration source position, due to the superior accuracy in dose calculation.
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Affiliation(s)
- Samira M Carvalho
- Institute of Radiation Protection and Dosimetry-IRD/CNEN, Rio de Janeiro, RJ, Brazil
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21
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Jovanovic Z, Krstic D, Nikezic D, Ros JMG, Ferrari P. MCNPX CALCULATIONS OF SPECIFIC ABSORBED FRACTIONS IN SOME ORGANS OF THE HUMAN BODY DUE TO APPLICATION OF 133Xe, 99mTc and 81mKr RADIONUCLIDES. RADIATION PROTECTION DOSIMETRY 2018; 178:422-429. [PMID: 29036660 DOI: 10.1093/rpd/ncx181] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Accepted: 08/30/2017] [Indexed: 06/07/2023]
Abstract
Monte Carlo simulations were performed to evaluate treatment doses with wide spread used radionuclides 133Xe, 99mTc and 81mKr. These different radionuclides are used in perfusion or ventilation examinations in nuclear medicine and as indicators for cardiovascular and pulmonary diseases. The objective of this work was to estimate the specific absorbed fractions in surrounding organs and tissues, when these radionuclides are incorporated in the lungs. For this purpose a voxel thorax model has been developed and compared with the ORNL phantom. All calculations and simulations were performed by means of the MCNP5/X code.
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Affiliation(s)
- Z Jovanovic
- Faculty of Science, University of Kragujevac, R. Domanovica 12, 34000 Kragujevac, Serbia
| | - D Krstic
- Faculty of Science, University of Kragujevac, R. Domanovica 12, 34000 Kragujevac, Serbia
| | - D Nikezic
- Faculty of Science, University of Kragujevac, R. Domanovica 12, 34000 Kragujevac, Serbia
| | | | - P Ferrari
- ENEA-Radiation Protection Institute, 4 Via Martiri di Monte Sole, 40129 Bologna (BO), Italy
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22
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Villoing D, Drozdovitch V, Simon SL, Kitahara CM, Linet MS, Melo DR. Estimated Organ Doses to Patients from Diagnostic Nuclear Medicine Examinations over Five Decades: 1960-2010. HEALTH PHYSICS 2017; 113:474-518. [PMID: 28968348 PMCID: PMC5679235 DOI: 10.1097/hp.0000000000000721] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Ionizing radiation exposure to the general U.S. population nearly doubled between 1980 and 2006, due almost entirely to the significant increase in the number of radiologic and nuclear medicine procedures performed. Significant changes in the types of procedures and radionuclides used in nuclear medicine, as well as in detection technology, have led to notable changes over time in absorbed doses to specific organs. This study is the first to estimate per-procedure organ doses to nuclear medicine patients and trends in doses over five decades. Weighted average organ doses per examination to 14 organs of interest were calculated for 17 examination types over 10 5-y time periods (1960-2010) as the product of the percentage of use of each radiopharmaceutical in those diagnostic procedures based on comprehensive literature review, the administered activity, and ICRP dose coefficients; doses per radiopharmaceutical were also provided for each organ, procedure, and time period. The weighted doses to adult nuclear medicine patients from cardiac procedures increased to all organs of interest between 1960 and 2010 except for the urinary bladder wall. From high radiation doses for most other procedures in the 1960s, with up to 0.7 Gy in the specific case of radioiodinated thyroid scans, organ-absorbed doses generally decreased from 1960 to 1990. In contrast, during the 1990s and 2000s, the weighted doses were gradually increased for some procedures, such as brain and skeleton scans. The increasing number of nuclear medicine procedures, specifically cardiac scans and changes in weighted doses, underscore the need to monitor exposure levels and radiation-related disease risks in nuclear medicine patients.
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Affiliation(s)
- Daphnée Villoing
- Radiation Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD, USA
| | - Vladimir Drozdovitch
- Radiation Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD, USA
| | - Steven L. Simon
- Radiation Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD, USA
| | - Cari M. Kitahara
- Radiation Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD, USA
| | - Martha S. Linet
- Radiation Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD, USA
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