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Zanzonico P. The MIRD Schema for Radiopharmaceutical Dosimetry: A Review. J Nucl Med Technol 2024; 52:74-85. [PMID: 38839128 DOI: 10.2967/jnmt.123.265668] [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: 09/20/2023] [Revised: 01/20/2024] [Indexed: 06/07/2024] Open
Abstract
Internal dosimetry evaluates the amount and spatial and temporal distributions of radiation energy deposited in tissue from radionuclides within the body. Historically, nuclear medicine had been largely a diagnostic specialty, and the implicitly performed risk-benefit analyses have been straightforward, with relatively low administered activities yielding important diagnostic information whose benefit far outweighs any potential risk associated with the attendant normal-tissue radiation doses. Although dose estimates based on anatomic models and population-average kinetics in this setting may deviate rather significantly from the actual normal-organ doses for individual patients, the large benefit-to-risk ratios are very forgiving of any such inaccuracies. It is in this context that the MIRD schema was originally developed and has been largely applied. The MIRD schema, created and maintained by the MIRD committee of the Society of Nuclear Medicine and Molecular Imaging, comprises the notation, terminology, mathematic formulas, and reference data for calculating tissue radiation doses from radiopharmaceuticals administered to patients. However, with the ongoing development of new radiopharmaceuticals and the increasing therapeutic application of such agents, internal dosimetry in nuclear medicine and the MIRD schema continue to evolve-from population-average and organ-level to patient-specific and suborgan to voxel-level to cell-level dose estimation. This article will review the basic MIRD schema, relevant quantities and units, reference anatomic models, and its adaptation to small-scale and patient-specific dosimetry.
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Affiliation(s)
- Pat Zanzonico
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York
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2
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Struelens L, Huet C, Broggio D, Dabin J, Desorgher L, Giussani A, Li WB, Nosske D, Lee YK, Cunha L, Carapinha MJR, Medvedec M, Covens P. Joint EURADOS-EANM initiative for an advanced computational framework for the assessment of external dose rates from nuclear medicine patients. EJNMMI Phys 2024; 11:38. [PMID: 38647987 PMCID: PMC11035505 DOI: 10.1186/s40658-024-00638-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: 10/10/2023] [Accepted: 03/28/2024] [Indexed: 04/25/2024] Open
Abstract
BACKGROUND In order to ensure adequate radiation protection of critical groups such as staff, caregivers and the general public coming into proximity of nuclear medicine (NM) patients, it is necessary to consider the impact of the radiation emitted by the patients during their stay at the hospital or after leaving the hospital. Current risk assessments are based on ambient dose rate measurements in a single position at a specified distance from the patient and carried out at several time points after administration of the radiopharmaceutical to estimate the whole-body retention. The limitations of such an approach are addressed in this study by developing and validating a more advanced computational dosimetry approach using Monte Carlo (MC) simulations in combination with flexible and realistic computational phantoms and time activity distribution curves from reference biokinetic models. RESULTS Measurements of the ambient dose rate equivalent Ḣ*(10) at 1 m from the NM patient have been successfully compared against MC simulations with 5 different codes using the ICRP adult reference computational voxel phantoms, for typical clinical procedures with 99mTc-HDP/MDP, 18FDG and Na131I. All measurement data fall in the 95% confidence intervals, determined for the average simulated results. Moreover, the different MC codes (MCNP-X, PHITS, GATE, GEANT4, TRIPOLI-4®) have been compared for a more realistic scenario where the effective dose rate Ė of an exposed individual was determined in positions facing and aside the patient model at 30 cm, 50 cm and 100 cm. The variation between codes was lower than 8% for all the radiopharmaceuticals at 1 m, and varied from 5 to 16% for the face-to face and side-by-side configuration at 30 cm and 50 cm. A sensitivity study on the influence of patient model morphology demonstrated that the relative standard deviation of Ḣ*(10) at 1 m for the range of included patient models remained under 16% for time points up to 120 min post administration. CONCLUSIONS The validated computational approach will be further used for the evaluation of effective dose rates per unit administered activity for a variety of close-contact configurations and a range of radiopharmaceuticals as part of risk assessment studies. Together with the choice of appropriate dose constraints this would facilitate the setting of release criteria and patient restrictions.
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Affiliation(s)
- Lara Struelens
- Belgian Nuclear Research Center (SCK CEN), Nuclear Medical Applications, Boeretang 200, 2400, Mol, Belgium.
| | - Christelle Huet
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSE-SANTE/SDOS, 31 Avenue de La Division Leclerc, 92260, Fontenay-Aux-Roses, France
| | - David Broggio
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSE-SANTE/SDOS, 31 Avenue de La Division Leclerc, 92260, Fontenay-Aux-Roses, France
| | - Jérémie Dabin
- Belgian Nuclear Research Center (SCK CEN), Nuclear Medical Applications, Boeretang 200, 2400, Mol, Belgium
| | - Laurent Desorgher
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Augusto Giussani
- Federal Office for Radiation Protection (BfS), Ingolstädter Landstr. 1, 85764, Oberschleißheim, Germany
| | - Wei Bo Li
- Federal Office for Radiation Protection (BfS), Ingolstädter Landstr. 1, 85764, Oberschleißheim, Germany
| | - Dietmar Nosske
- Federal Office for Radiation Protection (BfS), Ingolstädter Landstr. 1, 85764, Oberschleißheim, Germany
| | - Yi-Kang Lee
- Université Paris-Saclay, CEA, Service d'études des réacteurs et de mathématiques appliquées, 91191, Gif-Sur-Yvette, France
| | - Lidia Cunha
- Nuclear Medicine and Molecular Imaging, IsoPor-Azores, Canada do Breado, 9700, Angra Do Heroismo, Azores, Portugal
| | - Maria J R Carapinha
- ESTeSL-Escola Superior de Tecnologia da Saúde, Instituto Politécnico de Lisboa, Lisboa, Portugal
| | - Mario Medvedec
- Department of Nuclear Medicine and Radiation Protection, University Hospital Centre Zagreb, Zagreb, Croatia
| | - Peter Covens
- Molecular Imaging and Therapy, Vrije Universiteit Brussel (VUB), Brussels, Belgium
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Verfaillie G, Rutten J, D'Asseler Y, Bacher K. Accuracy of patient-specific CT organ doses from Monte Carlo simulations: influence of CT-based voxel models. Phys Eng Sci Med 2024:10.1007/s13246-024-01422-z. [PMID: 38634980 DOI: 10.1007/s13246-024-01422-z] [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: 09/26/2023] [Accepted: 04/01/2024] [Indexed: 04/19/2024]
Abstract
Monte Carlo simulations using patient CT images as input are the gold standard to perform patient-specific dosimetry. However, in standard clinical practice patient's CT images are limited to the reconstructed CT scan range. In this study, organ dose calculations were performed with ImpactMC for chest and cardiac CT using whole-body and anatomy-specific voxel models to estimate the accuracy of CT organ doses based on the latter model. When the 3D patient model is limited to the CT scan range, CT organ doses from Monte Carlo simulations are the most accurate for organs entirely in the field of view. For these organs only the radiation dose related to scatter from the rest of the body is not incorporated. For organs lying partially outside the field of view organ doses are overestimated by not accounting for the non-irradiated tissue mass. This overestimation depends strongly on the amount of the organ volume located outside the field of view. To get a more accurate estimation of the radiation dose to these organs, the ICRP reference organ masses and densities could form a solution. Except for the breast, good agreement in dose was found for most organs. Voxel models generated from clinical CT examinations do not include the overscan in the z-direction. The availability of whole-body voxel models allowed to study this influence as well. As expected, overscan induces slightly higher organ doses.
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Affiliation(s)
- Gwenny Verfaillie
- Department of Human Structure and Repair, Ghent University, Ghent, Belgium.
| | - Jeff Rutten
- Department of Human Structure and Repair, Ghent University, Ghent, Belgium
| | - Yves D'Asseler
- Department of Nuclear Medicine, Ghent University Hospital, Ghent, Belgium
- Department of Diagnostic Sciences, Ghent University, Ghent, Belgium
| | - Klaus Bacher
- Department of Human Structure and Repair, Ghent University, Ghent, Belgium
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Hoeijmakers EJI, Hoenen K, Bauwens M, Eekers DBP, Jeukens CRLPN, Wierts R. Dose rate conversion coefficients for ocular contamination in nuclear medicine: A Monte Carlo simulation with experimental validation. Med Phys 2024. [PMID: 38588509 DOI: 10.1002/mp.17073] [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: 12/05/2023] [Revised: 02/16/2024] [Accepted: 03/27/2024] [Indexed: 04/10/2024] Open
Abstract
BACKGROUND Since 2011, the International Commission on Radiological Protection (ICRP) has recommended an annual eye lens dose limit of 20 mSv for radiation workers, averaged over 5 years, with no year exceeding 50 mSv. However, limited research has been conducted on dose rate conversion coefficients (DCCs) for direct contamination of the eye. PURPOSE This study aimed to accurately determine DCCs for the eye lens and cornea for ocular contamination with radionuclides used in nuclear medicine. METHODS DCCs for 37 radionuclides used in nuclear medicine were determined using two different methods. Method 1 involved conducting Monte Carlo (MC) simulations of an ICRU cylinder to determine the absorbed dose at a depth of 3 mm resulting from a point source. The accuracy of this simulation approach was validated by experimental thermoluminescent dosimeter (TLD) measurements for 18F, 68Ga, 99mTc, and 177Lu. In method 2, average DCCs were calculated for the eye lens (complete and radiosensitive parts) and the cornea for both a point source and thin surface contamination centered on the cornea using MC simulations on the adult mesh-type reference computational phantom of the eye from the ICRP (MRCP). RESULTS DCCs determined from TLD measurements showed excellent agreement (deviations: +1.4%, +4.7%, -3.1%, and -2.5% for 18F, 68Ga, 99mTc, and 177Lu, respectively) compared to MC simulations of the experimental set-up. For the 37 radionuclides, DCCs of the complete eye-lens for a point source ranged from 2.53 × 10-7 to 4.15 × 10-2 mGy MBq-1 s-1 for the adult MRCPs, being substantially smaller compared to DCCs determined via MC simulations of a ICRU cylinder. In general, point source and surface contamination showed comparable DCCs for the eye lens. Radionuclides emitting low-energy beta radiation or conversion electrons (e.g., 177Lu, 99mTc) showed low DCCs as the radiation does not penetrate to the depth of the eye lens, while radionuclides emitting high-energy beta radiation (e.g., 90Y) showed high DCCs. Overall, DCCs for the radiosensitive part of the eye lens were larger (up to a factor of 3) compared to the complete eye lens. DCCs for the cornea were larger than for the eye lens with a factor that strongly depended on the emitted radiation type. Especially alpha emitters (e.g., 211At, 223Ra) showed high DCCs for the cornea because of the short range of alpha radiation, leading to local maxima in the cornea and not reaching the eye lens. CONCLUSION DCCs at a depth of 3 mm in an ICRU cylinder and adult MRCP DCCs for both the complete and sensitive parts of the eye lens and cornea were determined for 37 radionuclides having applications in nuclear medicine. These DCCs are highly useful in radiation safety assessments and radiation dose calculations in ocular contamination incidents.
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Affiliation(s)
- Eva J I Hoeijmakers
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Kes Hoenen
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Matthias Bauwens
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Daniëlle B P Eekers
- Department of Radiation Oncology (Maastro), GROW School for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Cécile R L P N Jeukens
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Roel Wierts
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Centre+, Maastricht, The Netherlands
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Faddegon B, Descovich M, Chen K, Ramos-Méndez J, Iii MR, Wahl N, Taylor P, Griffin K, Lee C. A digital male pelvis phantom series showing anatomical variations over the course of fractionated radiotherapy treatment. Med Phys 2024; 51:3034-3044. [PMID: 38071746 DOI: 10.1002/mp.16865] [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: 07/21/2023] [Revised: 11/08/2023] [Accepted: 11/08/2023] [Indexed: 04/05/2024] Open
Abstract
BACKGROUND Daily IGRT images show day-to-day anatomical variations in patients undergoing fractionated prostate radiotherapy. This is of particular importance in particle beam treatments. PURPOSE To develop a digital phantom series showing variation in pelvic anatomy for evaluating treatment planning and IGRT procedures in particle radiotherapy. METHODS A pelvic phantom series was developed from the planning MRI and kVCT (planning CT) images along with six of the daily serial MVCT images taken of a single patient treated with a full bladder on a Tomotherapy unit. The selected patient had clearly visible yet unexceptional internal anatomy variation. Prostate, urethra, bladder, rectum, bowel, bowel gas, bone and soft tissue were contoured and a single Hounsfield Unit was assigned to each region. Treatment plans developed on the kVCT for photon, proton and carbon beams were recalculated on each phantom to demonstrate a clinical application of the series. Proton plans were developed with and without robust optimization. RESULTS Limited to axial slices with prostate, the bladder volume varied from 6 to 46 cm3, the rectal volume (excluding gas) from 22 to 52 cm3, and rectal gas volume from zero to 18 cm3. The water equivalent path length to the prostate varied by up to 1.5 cm . The variations resulted in larger changes in the RBE-weighted Dose Volume Histograms of the non-robust proton plan and the carbon plan compared to the robust proton plan, the latter similar to the photon plan. The prostate coverage (V100%) decreased by an average of 18% in the carbon plan, 16% in the non-robust proton plan, 1.8% in the robust proton plan, and 4.4% in the photon plan. The volume of rectum receiving 75% of the prescription dose (V75%) increased by an average of 3.7 cm3, 4.7 cm3, 1.9 cm3, and 0.6 cm3 in those four plans, respectively. CONCLUSIONS The digital pelvic phantom series provides for quantitative investigation of IGRT procedures and new methods for improving accuracy in particle therapy and may be used in cross-institutional comparisons for clinical trial quality assurance.
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Affiliation(s)
- Bruce Faddegon
- Department of Radiation Oncology, University of California San Francisco, San Francisco, California, USA
| | - Martina Descovich
- Department of Radiation Oncology, University of California San Francisco, San Francisco, California, USA
| | - Katherine Chen
- Department of Radiation Oncology, University of California San Francisco, San Francisco, California, USA
| | - José Ramos-Méndez
- Department of Radiation Oncology, University of California San Francisco, San Francisco, California, USA
| | - Mack Roach Iii
- Department of Radiation Oncology, University of California San Francisco, San Francisco, California, USA
| | - Niklas Wahl
- Division of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Heidelberg Institute for Radiation Oncology (HIRO) and National Center for Radiation Research in Oncology (NCRO), Heidelberg, Germany
| | - Paige Taylor
- Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, Texas, USA
| | - Keith Griffin
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Choonsik Lee
- Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, Texas, USA
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
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Tolmachev SY, Avtandilashvili M. Long-term retention and distribution of highly enriched uranium in an occupationally exposed female. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2024; 63:109-123. [PMID: 38197921 DOI: 10.1007/s00411-023-01053-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Accepted: 12/08/2023] [Indexed: 01/11/2024]
Abstract
The United States Transuranium and Uranium Registries' (USTUR) female whole body tissue donor studied here was occupationally exposed to highly enriched uranium for 17 years. One hundred and twenty-nine tissue samples were collected at the time of death, 31 years post-exposure. These samples were radiochemically analyzed for uranium. The highest uranium concentration of 16.5 ± 2.0 µg kg-1 was measured in the lungs, and the lowest concentration of 0.11 ± 0.01 µg kg-1 in the liver. The thyroid had the highest concentration of 6.3 ± 2.9 µg kg-1 among systemic tissues. Mass-weighted average concentration in the entire skeleton was estimated to be 1.60 ± 0.19 µg kg-1. In the skeleton, uranium was non-uniformly distributed among different bones. Thirty-one years after the intake, approximately 40% of occupational uranium was still retained in the skeleton, followed by the kidneys (~ 30%), and the brain and liver (~ 10%). Systemic uranium was equally distributed between the skeleton and soft tissues. Uranium content in systemic organs followed the pattern: skeleton > > brain ≈ kidneys > heart ≈ liver > thyroid ≈ spleen. Uranium distribution in this female was compared to previously published USTUR data for male tissue donors. It is concluded that no difference in uranium systemic distribution was observed between female and male individuals. It is demonstrated that dose assessment based on the current ICRP biokinetic model overestimated the dose to the brain by 20%.
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Affiliation(s)
- Sergey Y Tolmachev
- United States Transuranium and Uranium Registries, College of Pharmacy and Pharmaceutical Sciences, Washington State University, 1845 Terminal Drive, Suite 201, Richland, WA, 99354-4959, USA.
| | - Maia Avtandilashvili
- United States Transuranium and Uranium Registries, College of Pharmacy and Pharmaceutical Sciences, Washington State University, 1845 Terminal Drive, Suite 201, Richland, WA, 99354-4959, USA
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Marquis H, Ocampo Ramos JC, Carter LM, Zanzonico P, Bolch WE, Laforest R, Kesner AL. MIRD Pamphlet No. 29: MIRDy90-A 90Y Research Microsphere Dosimetry Tool. J Nucl Med 2024; 65:jnumed.123.266743. [PMID: 38388514 PMCID: PMC11064830 DOI: 10.2967/jnumed.123.266743] [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: 10/03/2023] [Accepted: 01/23/2024] [Indexed: 02/24/2024] Open
Abstract
90Y-microsphere radioembolization has become a well-established treatment option for liver malignancies and is one of the first U.S. Food and Drug Administration-approved unsealed radionuclide brachytherapy devices to incorporate dosimetry-based treatment planning. Several different mathematical models are used to calculate the patient-specific prescribed activity of 90Y, namely, body surface area (SIR-Spheres only), MIRD single compartment, and MIRD dual compartment (partition). Under the auspices of the MIRDsoft initiative to develop community dosimetry software and tools, the body surface area, MIRD single-compartment, MIRD dual-compartment, and MIRD multicompartment models have been integrated into a MIRDy90 software worksheet. The worksheet was built in MS Excel to estimate and compare prescribed activities calculated via these respective models. The MIRDy90 software was validated against available tools for calculating 90Y prescribed activity. The results of MIRDy90 calculations were compared with those obtained from vendor and community-developed tools, and the calculations agreed well. The MIRDy90 worksheet was developed to provide a vetted tool to better evaluate patient-specific prescribed activities calculated via different models, as well as model influences with respect to varying input parameters. MIRDy90 allows users to interact and visualize the results of various parameter combinations. Variables, equations, and calculations are described in the MIRDy90 documentation and articulated in the MIRDy90 worksheet. The worksheet is distributed as a free tool to build expertise within the medical physics community and create a vetted standard for model and variable management.
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Affiliation(s)
- Harry Marquis
- 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
| | - Lukas M Carter
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Pat Zanzonico
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Wesley E Bolch
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida; and
| | - Richard Laforest
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri
| | - Adam L Kesner
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York;
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Cicone F, Sjögreen Gleisner K, Sarnelli A, Indovina L, Gear J, Gnesin S, Kraeber-Bodéré F, Bischof Delaloye A, Valentini V, Cremonesi M. The contest between internal and external-beam dosimetry: The Zeno's paradox of Achilles and the tortoise. Phys Med 2024; 117:103188. [PMID: 38042710 DOI: 10.1016/j.ejmp.2023.103188] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 11/06/2023] [Accepted: 11/23/2023] [Indexed: 12/04/2023] Open
Abstract
Radionuclide therapy, also called molecular radiotherapy (MRT), has come of age, with several novel radiopharmaceuticals being approved for clinical use or under development in the last decade. External beam radiotherapy (EBRT) is a well-established treatment modality, with about half of all oncologic patients expected to receive at least one external radiation treatment over their disease course. The efficacy and the toxicity of both types of treatment rely on the interaction of radiation with biological tissues. Dosimetry played a fundamental role in the scientific and technological evolution of EBRT, and absorbed doses to the target and to the organs at risk are calculated on a routine basis. In contrast, in MRT the usefulness of internal dosimetry has long been questioned, and a structured path to include absorbed dose calculation is missing. However, following a similar route of development as EBRT, MRT treatments could probably be optimized in a significant proportion of patients, likely based on dosimetry and radiobiology. In the present paper we describe the differences and the similarities between internal and external-beam dosimetry in the context of radiation treatments, and we retrace the main stages of their development over the last decades.
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Affiliation(s)
- Francesco Cicone
- Department of Experimental and Clinical Medicine, "Magna Graecia" University of Catanzaro, Catanzaro, Italy; Nuclear Medicine Unit, "Mater Domini" University Hospital, Catanzaro, Italy.
| | | | - Anna Sarnelli
- Medical Physics Unit, IRCCS Istituto Romagnolo per lo Studio dei Tumori (IRST) "Dino Amadori", Meldola, Italy
| | - Luca Indovina
- Department of Diagnostic Imaging, Oncological Radiotherapy and Hematology, Fondazione Policlinico Universitario "Agostino Gemelli" IRCCS, Rome, Italy
| | - Jonathan Gear
- Joint Department of Physics, Royal Marsden NHSFT & Institute of Cancer Research, Sutton, UK
| | - Silvano Gnesin
- Institute of Radiation Physics, Lausanne University Hospital, Lausanne, Switzerland; University of Lausanne, Lausanne, Switzerland
| | - Françoise Kraeber-Bodéré
- Nantes Université, Université Angers, CHU Nantes, INSERM, CNRS, CRCI2NA, Médecine Nucléaire, F-44000 Nantes, France
| | | | - Vincenzo Valentini
- Department of Diagnostic Imaging, Oncological Radiotherapy and Hematology, Fondazione Policlinico Universitario "Agostino Gemelli" IRCCS, Rome, Italy; Università Cattolica del Sacro Cuore, Rome, Italy
| | - Marta Cremonesi
- Unit of Radiation Research, IEO, European Institute of Oncology IRCCS, Milan, Italy
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Kwon TE, Chung Y, Lee C. Korean-specific iodine S values for use in internal dosimetry. NUCLEAR ENGINEERING AND TECHNOLOGY 2023; 55:4659-4663. [PMID: 38124777 PMCID: PMC10732341 DOI: 10.1016/j.net.2023.09.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2023]
Abstract
The use of iodine S values derived using the International Commission Radiological Protection (ICRP) phantoms may introduce significant bias in internal dosimetry for Koreans due to anatomical variability. In the current study, we produced an extensive dataset of Korean S values for selected five iodine radioisotopes (I-125, I-129, I-131, I-133, and I-134) for use in radiation protection. To calculate S values, we implemented Monte Carlo simulations using the Mesh-type Reference Korean Phantoms (MRKPs), developed in a high-quality/fidelity mesh format. Noticeable differences were observed in S value comparisons between the Korean and ICRP reference phantoms with ratios (Korean/ICRP) widely ranging from 0.16 to 6.2. The majority of S value ratios were lower than the unity in Korean phantoms (interquartile range =0.47-1.28; mean = 0.96; median = 0.69). The S values provided in the current study will be extensively utilized in iodine internal dosimetry for Koreans.
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Affiliation(s)
- Tae-Eun Kwon
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD 20850, United States of America
| | - Yoonsun Chung
- Department of Nuclear Engineering, Hanyang University, Seoul, 04763, South Korea
| | - Choonsik Lee
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD 20850, United States of America
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Hetrick L, Douglas J, Poudel D. Practical overview of the ICRP Publication 145 phantoms for use with MCNP. RADIATION PROTECTION DOSIMETRY 2023; 199:2328-2337. [PMID: 37635187 DOI: 10.1093/rpd/ncad233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 06/09/2023] [Accepted: 07/03/2023] [Indexed: 08/29/2023]
Abstract
This paper provides a practical overview of the mesh-type reference phantoms (MRCPs) published by the ICRP by providing supplementary guidance on the proper implementation of using the MRCPs in computational codes, such as Monte Carlo N-Particle. Various validation scenarios for photon and neutron exposures were also examined where published values were reproduced using the MRCPs for both external and internal exposures. Generally, the MRCPs performed well in the validation scenarios with the values reproduced being within 10% of the published values.
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Affiliation(s)
- Lucas Hetrick
- Los Alamos National Laboratory, Los Alamos, NM 87545, United States
| | - Jordan Douglas
- Los Alamos National Laboratory, Los Alamos, NM 87545, United States
| | - Deepesh Poudel
- Los Alamos National Laboratory, Los Alamos, NM 87545, United States
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Beekman C, Withrow JD, Correa Alfonso CM, Pathak SP, Dawson RJ, Carrasco-Rojas N, Sforza AR, Colon CG, Bolch WE, Grassberger C, Paganetti H. A stochastic model of blood flow to calculate blood dose during radiotherapy. Phys Med Biol 2023; 68:10.1088/1361-6560/ad02d6. [PMID: 37827171 PMCID: PMC10695181 DOI: 10.1088/1361-6560/ad02d6] [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: 05/31/2023] [Accepted: 10/12/2023] [Indexed: 10/14/2023]
Abstract
Purpose. Lymphopenia is a common side effect in patients treated with radiotherapy, potentially caused by direct cell killing of circulating lymphocytes in the blood. To investigate this hypothesis, a method to assess dose to circulating lymphocytes is needed.Methods. A stochastic model to simulate systemic blood flow in the human body was developed based on a previously designed compartment model. Blood dose was obtained by superimposing the spatiotemporal distribution of blood particles with a time-varying dose rate field, and used as a surrogate for dose to circulating lymphocytes. We discuss relevant theory on compartmental modeling and how to combine it with models of explicit organ vasculature.Results. A general workflow was established which can be used for any anatomical site. Stochastic compartments can be replaced by explicit models of organ vasculatures for improved spatial resolution, and tumor compartments can be dynamically assigned. Generating a patient-specific blood flow distribution takes about one minute, fast enough to investigate the effect of varying treatment parameters such as the dose rate. Furthermore, the anatomical structures contributing most to the overall blood dose can be identified, which could potentially be used for lymphocyte-sparing treatment planning.Conclusion. The ability to report the blood dose distribution during radiotherapy is imperative to test and act upon the current paradigm that radiation-induced lymphopenia is caused by direct cell killing of lymphocytes in the blood. We have built a general model that can do so for various treatment sites. The presented framework is publicly available athttp://github.com/mghro/hedos.
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Affiliation(s)
- Chris Beekman
- Massachusetts General Hospital/Harvard Medical School, United States of America
| | | | | | | | | | | | | | | | | | - Clemens Grassberger
- Massachusetts General Hospital/Harvard Medical School, United States of America
- University of Washington, United States of America
| | - Harald Paganetti
- Massachusetts General Hospital/Harvard Medical School, United States of America
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Kesner AL, Carter LM, Bolch WE. Addendum to MIRD Pamphlet No. 28. J Nucl Med 2023; 64:1668. [PMID: 37562805 PMCID: PMC10586485 DOI: 10.2967/jnumed.123.266325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 07/17/2023] [Indexed: 08/12/2023] Open
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13
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Azarkin M, Kirakosyan M, Ryabov V. Study of Nuclear Reactions in Therapy of Tumors with Proton Beams. Int J Mol Sci 2023; 24:13400. [PMID: 37686211 PMCID: PMC10488192 DOI: 10.3390/ijms241713400] [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: 07/21/2023] [Revised: 08/17/2023] [Accepted: 08/25/2023] [Indexed: 09/10/2023] Open
Abstract
This paper presents an assessment of nuclear reaction yields of protons, α-particles, and neutrons in human tissue-equivalentmaterial in proton therapy using a simulation with Geant 4. In this study, we also check an enhancement of nuclear reactions due to the presence of Bi, Au, 11B, and 10B radiosensitizer nanoparticles. We demonstrate that a proton beam induces a noticeable amount of nuclear reactions in the tissue. Nevertheless, the enhancement of nuclear reaction products due to radiosensitizer nanoparticles is found to be negligible.
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Affiliation(s)
- Maxim Azarkin
- P. N. Lebedev Physical Institute, 119991 Moscow, Russia; (M.K.); (V.R.)
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14
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Kong X, Wang Y, Huang J, Zhang W, Du C, Yin Y, Xue H, Gao H, Liu K, Wu T, Sun L. Microdosimetric assessment about proton spread-out Bragg peak at different depths based on the normal human mesh-type cell population model. Phys Med Biol 2023; 68:175010. [PMID: 37578025 DOI: 10.1088/1361-6560/acec2b] [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: 02/09/2023] [Accepted: 07/31/2023] [Indexed: 08/15/2023]
Abstract
Objective.In clinical proton therapy, the spread-out Bragg peak (SOBP) is commonly used to fit the target shape. Dose depositions at microscopic sites vary, even with a consistent absorbed dose (D) in SOBP. In the present study, monolayer mesh-type cell population models were developed for microdosimetric assessment at different SOBP depths.Approach.Normal human bronchial epithelial (BEAS-2B) and hepatocytes (L-O2) mesh-type cell models were constructed based on fluorescence tomography images of normal human cells. Particle transport simulation in cell populations was performed coupled with Monte Carlo software PHITS. The relationship between microdosimetry and macrodosimetry of SOBP at different depths was described by analyzing the microdosimetric indicators such as specific energyz,specific energy distributionfz,D,and relative standard deviationσz/z¯within cells. Additionally, the microdosimetric distributions characteristics and their contributing factors were also discussed.Main results.The microscopic dose distribution is strongly influenced by cellular size, shape, and material. The mean specific energyz¯of nucleus and cytoplasm in the cell population is greater than the overall absorbed dose of the cell population model (Dp), with a maximumz¯/Dpof 1.1. The cellular dose distribution is different between the BEAS-2B mesh-type model and its concentric ellipsoid geometry-type model, which difference inz¯is about 10.3% for the nucleus and about 7.5% for the cytoplasm with the SOBP depth of 15 cm. WhenD= 2 Gy, the maximumzof L-O2 nucleus reaches 2.8 Gy andσz/z¯is 5.1% at the mid-depth SOBP (16-18 cm); while the maximumzof the BEAS-2B nucleus reaches 2.2 Gy with only 2.7% ofσz/z¯.Significance.The significant variation of microdosimetric distributions of SOBP different depths indicates the necessity to use mesh-type cell population models, which have the potential to be compared with biological results and build the bio-physical model.
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Affiliation(s)
- Xianghui Kong
- State Key Laboratory of Radiation Medicine and Protection, Suzhou 215123, People's Republic of China
- School of Radiation Medicine and Protection, Soochow University, Suzhou 215123, People's Republic of China
- Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou 215123, People's Republic of China
| | - Yidi Wang
- State Key Laboratory of Radiation Medicine and Protection, Suzhou 215123, People's Republic of China
- School of Radiation Medicine and Protection, Soochow University, Suzhou 215123, People's Republic of China
- Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou 215123, People's Republic of China
| | - Jiachen Huang
- State Key Laboratory of Radiation Medicine and Protection, Suzhou 215123, People's Republic of China
- School of Radiation Medicine and Protection, Soochow University, Suzhou 215123, People's Republic of China
- Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou 215123, People's Republic of China
| | - Wenyue Zhang
- State Key Laboratory of Radiation Medicine and Protection, Suzhou 215123, People's Republic of China
- School of Radiation Medicine and Protection, Soochow University, Suzhou 215123, People's Republic of China
- Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou 215123, People's Republic of China
| | - Chuansheng Du
- State Key Laboratory of Radiation Medicine and Protection, Suzhou 215123, People's Republic of China
- School of Radiation Medicine and Protection, Soochow University, Suzhou 215123, People's Republic of China
- Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou 215123, People's Republic of China
| | - Yuchen Yin
- State Key Laboratory of Radiation Medicine and Protection, Suzhou 215123, People's Republic of China
- School of Radiation Medicine and Protection, Soochow University, Suzhou 215123, People's Republic of China
- Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou 215123, People's Republic of China
| | - Huiyuan Xue
- State Key Laboratory of Radiation Medicine and Protection, Suzhou 215123, People's Republic of China
- School of Radiation Medicine and Protection, Soochow University, Suzhou 215123, People's Republic of China
- Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou 215123, People's Republic of China
| | - Han Gao
- State Key Laboratory of Radiation Medicine and Protection, Suzhou 215123, People's Republic of China
- School of Radiation Medicine and Protection, Soochow University, Suzhou 215123, People's Republic of China
- Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou 215123, People's Republic of China
| | - Kun Liu
- State Key Laboratory of Radiation Medicine and Protection, Suzhou 215123, People's Republic of China
- School of Radiation Medicine and Protection, Soochow University, Suzhou 215123, People's Republic of China
- Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou 215123, People's Republic of China
| | - Tao Wu
- State Key Laboratory of Radiation Medicine and Protection, Suzhou 215123, People's Republic of China
- School of Radiation Medicine and Protection, Soochow University, Suzhou 215123, People's Republic of China
- Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou 215123, People's Republic of China
| | - Liang Sun
- State Key Laboratory of Radiation Medicine and Protection, Suzhou 215123, People's Republic of China
- School of Radiation Medicine and Protection, Soochow University, Suzhou 215123, People's Republic of China
- Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou 215123, People's Republic of China
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15
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Wang Y, Kong D, Gao H, Du C, Xue H, Liu K, Kong X, Zhang W, Yin Y, Wu T, Jiao Y, Sun L. Multiple Mesh-type Real Human Cell Models for Dosimetric Application Coupled with Monte Carlo Simulations. Radiat Res 2023; 200:176-187. [PMID: 37410090 DOI: 10.1667/rade-23-00020.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 06/14/2023] [Indexed: 07/07/2023]
Abstract
The mesh-type models are superior to voxel models in cellular dose assessment coupled with Monte Carlo codes. The aim of this study was to expand the micron-scale mesh-type models based on the fluorescence tomography of real human cells, and to investigate the feasibility of these models in the application of various irradiation scenarios and Monte Carlo codes. Six different human cell lines, including pulmonary epithelial BEAS-2B, embryonic kidney 293T, hepatocyte L-02, B-lymphoblastoid HMy2.CIR, Gastric mucosal GES-1, and intestine epithelial FHs74Int, were adopted for single mesh-type models reconstruction and optimization based on laser confocal tomography images. Mesh-type models were transformed into the format of polygon mesh and tetrahedral mesh for the GATE and PHITS Monte Carlo codes, respectively. The effect of model reduction was analyzed by dose assessment and geometry consideration. The cytoplasm and nucleus doses were obtained by designating monoenergetic electrons and protons as external irradiation, and S values with different "target-source" combinations were calculated by assigning radioisotopes as internal exposure. Four kinds of Monte Carlo codes were employed, i.e., GATE with "Livermore," "Standard" and "Standard and Geant4-DNA mixed" models for electrons and protons, as well as PHITS with "EGS" mode for electrons and radioisotopes. Multiple mesh-type real human cellular models can be applied to Monte Carlo codes directly without voxelization when combined with certain necessary surface reduction. Relative deviations between different cell types were observed among various irradiation scenarios. The relative deviation of nucleus S value reaches up to 85.65% between L-02 and GES-1 cells by 3H for the "nucleus-nucleus" combination, while that of 293T and FHs74Int nucleus dose for external beams at a 5.12 cm depth of water is 106.99%. Nucleus with smaller volume is far more affected by physical codes. There is a considerable deviation for dose within BEAS-2B at the nanoscale. The multiple mesh-type real cell models were more versatile than voxel models and mathematical models. The present study provided several models which can easily be extended to other cell types and irradiation scenarios for RBE estimations and biological effect predictions, including radiation biological experiments, radiotherapy and radiation protection.
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Affiliation(s)
- YiDi Wang
- State Key Laboratory of Radiation Medicine and Protection, Suzhou, China
- School of Radiation Medicine and Protection, Soochow University, Suzhou, China
- Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou, China
| | - Dong Kong
- Department of Radiation Oncology, Affiliated Hospital of Jiangnan University, Wuxi, China
| | - Han Gao
- State Key Laboratory of Radiation Medicine and Protection, Suzhou, China
- School of Radiation Medicine and Protection, Soochow University, Suzhou, China
- Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou, China
| | - ChuanSheng Du
- State Key Laboratory of Radiation Medicine and Protection, Suzhou, China
- School of Radiation Medicine and Protection, Soochow University, Suzhou, China
- Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou, China
| | - HuiYuan Xue
- State Key Laboratory of Radiation Medicine and Protection, Suzhou, China
- School of Radiation Medicine and Protection, Soochow University, Suzhou, China
- Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou, China
| | - Kun Liu
- State Key Laboratory of Radiation Medicine and Protection, Suzhou, China
- School of Radiation Medicine and Protection, Soochow University, Suzhou, China
- Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou, China
| | - XiangHui Kong
- State Key Laboratory of Radiation Medicine and Protection, Suzhou, China
- School of Radiation Medicine and Protection, Soochow University, Suzhou, China
- Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou, China
| | - WenYue Zhang
- State Key Laboratory of Radiation Medicine and Protection, Suzhou, China
- School of Radiation Medicine and Protection, Soochow University, Suzhou, China
- Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou, China
| | - YuChen Yin
- State Key Laboratory of Radiation Medicine and Protection, Suzhou, China
- School of Radiation Medicine and Protection, Soochow University, Suzhou, China
- Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou, China
| | - Tao Wu
- State Key Laboratory of Radiation Medicine and Protection, Suzhou, China
- School of Radiation Medicine and Protection, Soochow University, Suzhou, China
- Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou, China
| | - Yang Jiao
- State Key Laboratory of Radiation Medicine and Protection, Suzhou, China
- School of Radiation Medicine and Protection, Soochow University, Suzhou, China
- Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou, China
| | - Liang Sun
- State Key Laboratory of Radiation Medicine and Protection, Suzhou, China
- School of Radiation Medicine and Protection, Soochow University, Suzhou, China
- Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou, China
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Lyu T, Zhao W, Gao W, Zhu J, Xi Y, Chen Y, Zhu W. A Dual-Energy Metal Artifact Redcution Method for DECT Image Reconstruction. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2023; 2023:1-6. [PMID: 38083063 DOI: 10.1109/embc40787.2023.10340221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2023]
Abstract
Metal implants are one of the culprits for image quality degradation in CT imaging, introducing so-called metal artifacts. With the help of the virtual-monochromatic imaging technique, dual-energy CT has been proven to be effective in metal artifact reduction. However, the virtual monochromatic images with suppressed metal artifacts show reduced CNR compared to polychromatic images. To remove metal artifacts on polychromatic images, we propose a dual-energy NMAR (deNMAR) algorithm in this paper that adds material decomposition to the widely used NMAR framework. The dual energy sinograms are first decomposed into water and bone sinograms, and metal regions are replaced with water on the reconstructed material maps. Prior sinograms are constructed by polyenergetically forward projecting the material maps with corresponding spectra, and they are used to guide metal trace interpolation in the same way as in the NMAR algorithm. We performed experiments on authentic human body phantoms, and the results show that the proposed deNMAR algorithm achieves better performance in tissue restoration compared to other compelling methods. Tissue boundaries become clear around metal implants, and CNR rises to 2.58 from ~1.70 on 80 kV images compared to other dual-energy-based algorithms.
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17
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Han H, Choi JW, Lee Y, Lee SM, Kim CH, Choi HJ, Yeom YS. An Investigation of Body Size Impact on Organ Doses for Neutron External Exposures Using the MRCP-based Phantom Library. HEALTH PHYSICS 2023; 124:316-325. [PMID: 36696362 DOI: 10.1097/hp.0000000000001672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
ABSTRACT In a recent study, a comprehensive library composed of 212 phantoms with different body sizes was established by deforming the adult male and female mesh-type reference computational phantoms (MRCPs) of ICRP Publication 145 and the next-generation ICRP reference phantoms over the current voxel-type reference phantoms of ICRP Publication 110. In this study, as an application of the MRCP-based phantom library, we investigated dosimetric impacts due to the different body sizes for neutron external exposures. A comprehensive dataset of organ/tissue dose coefficients (DCs) for idealized external neutron beams with four phantoms for each sex representatively selected from the phantom library were produced by performing Monte Carlo simulations using the Geant4 code. The body size-dependent DCs produced in this study were systematically analyzed, observing that the variation of the body weights overall played a more important role in organ/tissue dose calculations than the variation of the body heights. We also observed that the reference body-size DCs based on the MRCPs indeed significantly under- or overestimated the DCs produced using the phantoms, especially for those much heavier (male: 175 cm and 140 kg; female: 165 cm and 140 kg) than the reference body sizes (male: 176 cm and 73 kg; female: 163 cm and 60 kg) by up to 1.6 or 3.3 times, respectively. We believe that the use of the body size-dependent DCs, together with the reference body-size DCs, should be beneficial for more reliable organ/tissue dose estimates of individuals considering their body sizes rather than the most common conventional approach, i.e., the sole use of the reference body size DCs.
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Affiliation(s)
| | | | - Yumi Lee
- Department of Radiation Convergence Engineering, Yonsei University, Republic of Korea
| | - Soo Min Lee
- Department of Radiation Convergence Engineering, Yonsei University, Republic of Korea
| | - Chan Hyeong Kim
- Department of Nuclear Engineering, Hanyang University, Republic of Korea
| | - Hyun Joon Choi
- Department of Radiation Oncology, Yonsei University Wonju College of Medicine, Republic of Korea
| | - Yeon Soo Yeom
- Department of Radiation Convergence Engineering, Yonsei University, Republic of Korea
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Saldarriaga Vargas C, Andersson M, Bouvier-Capely C, Li WB, Madas B, Covens P, Struelens L, Strigari L. Heterogeneity of absorbed dose distribution in kidney tissues and dose–response modelling of nephrotoxicity in radiopharmaceutical therapy with beta-particle emitters: A review. Z Med Phys 2023:S0939-3889(23)00037-5. [PMID: 37031068 DOI: 10.1016/j.zemedi.2023.02.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 02/20/2023] [Accepted: 02/27/2023] [Indexed: 04/08/2023]
Abstract
Absorbed dose heterogeneity in kidney tissues is an important issue in radiopharmaceutical therapy. The effect of absorbed dose heterogeneity in nephrotoxicity is, however, not fully understood yet, which hampers the implementation of treatment optimization by obscuring the interpretation of clinical response data and the selection of optimal treatment options. Although some dosimetry methods have been developed for kidney dosimetry to the level of microscopic renal substructures, the clinical assessment of the microscopic distribution of radiopharmaceuticals in kidney tissues currently remains a challenge. This restricts the anatomical resolution of clinical dosimetry, which hinders a thorough clinical investigation of the impact of absorbed dose heterogeneity. The potential of absorbed dose-response modelling to support individual treatment optimization in radiopharmaceutical therapy is recognized and gaining attraction. However, biophysical modelling is currently underexplored for the kidney, where particular modelling challenges arise from the convolution of a complex functional organization of renal tissues with the function-mediated dose distribution of radiopharmaceuticals. This article reviews and discusses the heterogeneity of absorbed dose distribution in kidney tissues and the absorbed dose-response modelling of nephrotoxicity in radiopharmaceutical therapy. The review focuses mainly on the peptide receptor radionuclide therapy with beta-particle emitting somatostatin analogues, for which the scientific literature reflects over two decades of clinical experience. Additionally, detailed research perspectives are proposed to address various identified challenges to progress in this field.
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19
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Cumur C, Fujibuchi T, Arakawa H, Hamada K. Dose estimation for cone-beam computed tomography in image-guided radiation therapy for pelvic cancer using adult mesh-type reference computational phantoms. Radiol Phys Technol 2023; 16:203-211. [PMID: 36877400 DOI: 10.1007/s12194-023-00708-3] [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: 08/19/2022] [Revised: 02/24/2023] [Accepted: 02/24/2023] [Indexed: 03/07/2023]
Abstract
The use of cone-beam computed tomography (CBCT) is expanding owing to its installation in linear accelerators for radiation therapy, and the imaging dose induced by this system has become the center of attention. Here, the dose to patients caused by the CBCT imager was investigated. Organ doses and effective doses for male and female mesh-type reference computational phantoms (MRCPs) and pelvis CBCT mode, routinely used for pelvic irradiation, were estimated using the Particle and Heavy Ion Transport Code System. The simulation results were confirmed based on the point-dose measurements. The estimated organ doses for male MRCPs with/without raised arms and for female MRCPs with/without raised arms were 0.00286-35.6 mGy, 0.00286-35.1 mGy, 0.00933-39.5 mGy, and 0.00931-39.0 mGy, respectively. The anticipated effective doses for male MRCPs with/without raised arms and female MRCPs with/without raised arms irradiated by pelvis CBCT mode were 4.25 mSv, 4.16 mSv, 7.66 mSv, and 7.48 mSv, respectively. The results of this study will be useful for patients who undergo image-guided radiotherapy with CBCT. However, because this study only covered one type of cancer with one type of imager, and image quality was not considered, more studies should be conducted to estimate the radiation dose from imaging devices in radiation therapy.
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Affiliation(s)
- Ceyda Cumur
- Graduate School of Medical Sciences, Division of Medical Quantum Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-Ku, Fukuoka, 812-8582, Japan.
| | - Toshioh Fujibuchi
- Faculty of Medical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-Ku, Fukuoka, 812-8582, Japan
| | - Hiroyuki Arakawa
- Faculty of Medical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-Ku, Fukuoka, 812-8582, Japan
| | - Keisuke Hamada
- Department of Radiological Technology, National Hospital Organization Kyushu Cancer Center, 3-1-1, Notame Minami-Ku, Fukuoka, 811-1395, Japan
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20
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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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Qu S, Liu H, Xie T, Giger ML, Quan G, Zaidi H. Patient-specific fetal radiation dosimetry for pregnant patients undergoing abdominal and pelvic CT imaging. Med Phys 2023. [PMID: 36799714 DOI: 10.1002/mp.16304] [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: 08/03/2022] [Revised: 01/18/2023] [Accepted: 01/31/2023] [Indexed: 02/18/2023] Open
Abstract
BACKGROUND Accurate estimation of fetal radiation dose is crucial for risk-benefit analysis of radiological imaging, while the radiation dosimetry studies based on individual pregnant patient are highly desired. PURPOSE To use Monte Carlo calculations for estimation of fetal radiation dose from abdominal and pelvic computed tomography (CT) examinations for a population of patients with a range of variations in patients' anatomy, abdominal circumference, gestational age (GA), fetal depth (FD), and fetal development. METHODS Forty-four patient-specific pregnant female models were constructed based on CT imaging data of pregnant patients, with gestational ages ranging from 8 to 35 weeks. The simulation of abdominal and pelvic helical CT examinations was performed on three validated commercial scanner systems to calculate organ-level fetal radiation dose. RESULTS The absorbed radiation dose to the fetus ranged between 0.97 and 2.24 mGy, with an average of 1.63 ± 0.33 mGy. The CTDIvol -normalized fetal dose ranged between 0.56 and 1.30, with an average of 0.94 ± 0.25. The normalized fetal organ dose showed significant correlations with gestational age, maternal abdominal circumference (MAC), and fetal depth. The use of ATCM technique increased the fetal radiation dose in some patients. CONCLUSION A technique enabling the calculation of organ-level radiation dose to the fetus was developed from models of actual anatomy representing a range of gestational age, maternal size, and fetal position. The developed maternal and fetal models provide a basis for reliable and accurate radiation dose estimation to fetal organs.
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Affiliation(s)
- Shuiyin Qu
- Institute of Radiation Medicine, Fudan University, Shanghai, China.,Department of Engineering Physics, Tsinghua University, Beijing, China
| | - Haikuan Liu
- Institute of Radiation Medicine, Fudan University, Shanghai, China
| | - Tianwu Xie
- Institute of Radiation Medicine, Fudan University, Shanghai, China.,Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, Geneva, Switzerland
| | - Maryellen L Giger
- University of Chicago, Department of Radiology, Committee on Medical Physics, Chicago, Illinois, USA
| | - Guotao Quan
- Shanghai United Imaging Intelligence Co., Ltd., Shanghai, China
| | - Habib Zaidi
- Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, Geneva, Switzerland.,Geneva Neuroscience Center, Geneva University, 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
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Luo X, Qiu R, Wu Z, Yan S, Zhang H, Li J. A body-size-dependent series of Chinese adult standing phantoms for radiation dosimetry. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2023; 43:011501. [PMID: 36538816 DOI: 10.1088/1361-6498/acad0d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 12/20/2022] [Indexed: 06/17/2023]
Abstract
Phantoms of different sizes, as indicated by several studies, have a significant impact on the accuracy of dose calculations. Therefore, it is necessary to establish a body-size-dependent series of Chinese standing adult phantoms to improve the accuracy of radiation dosimetry. In this study, the Chinese reference polygon-mesh phantomsCRAM_S/CRAF_Shave been refined and a method for automatically constructing lymph nodes in a mesh phantom has been proposed. Then, based on the refined phantoms, this study has developed 42 anthropometric standing adult computational phantoms, 21 models for each gender, with a height range of 145-185 cm and weight as a function of body mass index corresponding to healthy, overweight and obese. The parameters were extracted from the National Occupational Health Standards (GBZ) document of the People's Republic of China, which covers more than 90% of the Chinese population. For a given body height and mass, phantoms are scaled in proportion to a factor reflecting the change of adipose tissue and the internal organs. The remainder is adjusted manually to match the target parameters. In addition, the constructed body-size-specific phantoms have been implemented in the in-house THUDose Monte Carlo code to calculate the dose coefficients (DCs) for external photon exposures in the antero-posterior, postero-anterior and right lateral geometries. The results showed that organ DCs varied significantly with body size at low energies (<2MeV) and high energies (>8MeV) due to the differences in anatomy. Organ DC differences between a phantom of a given size and a reference phantom vary by up to 40% for the same height and up to 400% for the whole phantom. The influence of body size differences on the DCs demonstrates that the body-size-dependent Chinese adult phantoms hold great promise for a wide range of applications in radiation dosimetry.
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Affiliation(s)
- Xiyu Luo
- Department of Engineering Physics, Tsinghua University, Beijing, People's Republic of China
- Key Laboratory of Particle and Radiation Imaging, Tsinghua University, Ministry of Education, Beijing, People's Republic of China
| | - Rui Qiu
- Department of Engineering Physics, Tsinghua University, Beijing, People's Republic of China
- Key Laboratory of Particle and Radiation Imaging, Tsinghua University, Ministry of Education, Beijing, People's Republic of China
| | - Zhen Wu
- Department of Engineering Physics, Tsinghua University, Beijing, People's Republic of China
- Nuctech Company Limited, Beijing, People's Republic of China
| | - Shuchang Yan
- Department of Engineering Physics, Tsinghua University, Beijing, People's Republic of China
- Key Laboratory of Particle and Radiation Imaging, Tsinghua University, Ministry of Education, Beijing, People's Republic of China
| | - Hui Zhang
- Department of Engineering Physics, Tsinghua University, Beijing, People's Republic of China
- Key Laboratory of Particle and Radiation Imaging, Tsinghua University, Ministry of Education, Beijing, People's Republic of China
| | - Junli Li
- Department of Engineering Physics, Tsinghua University, Beijing, People's Republic of China
- Key Laboratory of Particle and Radiation Imaging, Tsinghua University, Ministry of Education, Beijing, People's Republic of China
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23
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SIZE-specific dose estimate for lower-limb CT. Phys Eng Sci Med 2022; 45:1183-1191. [PMID: 36315380 DOI: 10.1007/s13246-022-01186-4] [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: 07/27/2022] [Accepted: 10/03/2022] [Indexed: 12/14/2022]
Abstract
The Computed Tomography Dose Index (CTDI) is an indicator for dose management in computed tomography (CT), but has limited use for patient dosimetry. To evaluate the patient dose, the size-specific dose estimate (SSDE), reported by the American Association of Physics in Medicine task groups 204, 220, and 293, must be calculated by the CTDIvol(z) displayed on the CT console, and the conversion factor f(D(z)) from the effective diameter (DEff) or water equivalent diameter (Dw). However, no reports have verified the appropriateness of using the 320-mm diameter phantom for dose assessment in CT examinations involving the lower limbs. Therefore, we validated a new method for evaluating the SSDE(z) of the lower limbs, using two 160-mm diameter phantoms instead of the 320-mm diameter phantom. The CTDIvol(z) obtained from Monte Carlo (MC) simulation study was reliable because they were almost the same as obtained in a dosimetry study. The conversion factor f (D (zl.l.)) for the lower limbs was evaluated based on the CTDIvol(z) obtained by MC simulation performed using two polymethyl methacrylate cylinder phantoms of 160-mm diameter. The MC simulation was performed by the International Commission on Radiological Protection publication 135 reference adult phantom and was used to evaluate the absorbed dose of the pelvis, thighs, knees, and ankles. The dose showing the greatest difference was the thighs, which was 8.3 mGy (16%) lower than the absorbed dose. Thus, the SSDE (zl.l.) could be estimated from the [Formula: see text] displayed on the CT scanner console.
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24
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Kobayashi M. [Useful Simulations for Research and Education]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2022; 78:1361-1366. [PMID: 36403969 DOI: 10.6009/jjrt.2022-2101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- Masanao Kobayashi
- Faculty of Radiological Technology, School of Health Siences, Fujita Health University
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25
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Ghalbzouri TE, Bardouni TE, Bakkali JE, Satti H, Arectout A, Berriban I, Nouayti A, Yerrou R. Photon-specific absorbed fraction estimates in stylized ORNL and voxelized ICRP adult male phantoms using a new developed Geant4-based code "DoseCalcs": a validation study. Radiol Phys Technol 2022; 15:323-339. [PMID: 36065049 DOI: 10.1007/s12194-022-00672-4] [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: 03/29/2022] [Revised: 08/12/2022] [Accepted: 08/13/2022] [Indexed: 10/14/2022]
Abstract
When a radiotracer is injected into a patient's body as part of a nuclear medicine investigation, the entire body is exposed to the ionizing radiation emitted, which can cause biological damage. Therefore, it is important to predict the internal radiation dose to properly balance the advantages of radiological examinations. Currently, various Monte Carlo tools, such as MCNP, Geant4, and GATE, are available to estimate internal radiation dosimetry-related quantities, such as S values (S) and specific absorbed fractions (SAF). Such codes make physics easier for physicists who are experienced with computer programming; however, programming and/or simulation inputs remain a time-consuming and intensive task. In this study, we present a newly developed Geant4-based code for internal dosimetry calculations, namely "DoseCalcs". To assess the performance of the geometrical methods and computational capabilities of our developed tool, we used the GDML, TEXT, STL, and C++ methods to model the ORNL adult phantom, and a voxel-based structure to construct the ICRP adult male. SAFs in the ORNL and ICRP adult male phantoms for eight discrete mono-energetic photons with energies ranging from 0.01 to 2 MeV are calculated with DoseCalcs and compared to ORNL and OpenDose reference data. The two phantoms showed good agreement with both references, which indicates the accuracy of DoseCalcs for subsequent use in estimating internal dosimetry quantities using a variety of geometrical methods.
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Affiliation(s)
- Tarik El Ghalbzouri
- ERSN Laboratory, Physics Department, Faculty of Sciences, University Abdelmalek Essaadi, Tetouan, Morocco.
| | - Tarek El Bardouni
- ERSN Laboratory, Physics Department, Faculty of Sciences, University Abdelmalek Essaadi, Tetouan, Morocco
| | - Jaafar El Bakkali
- ERSN Laboratory, Physics Department, Faculty of Sciences, University Abdelmalek Essaadi, Tetouan, Morocco.,Nuclear Medicine Department, Military Hospital Mohammed V, Rabat, Morocco
| | - Hicham Satti
- ERSN Laboratory, Physics Department, Faculty of Sciences, University Abdelmalek Essaadi, Tetouan, Morocco
| | - Assia Arectout
- ERSN Laboratory, Physics Department, Faculty of Sciences, University Abdelmalek Essaadi, Tetouan, Morocco
| | - Iman Berriban
- ERSN Laboratory, Physics Department, Faculty of Sciences, University Abdelmalek Essaadi, Tetouan, Morocco
| | - A Nouayti
- ERSN Laboratory, Physics Department, Faculty of Sciences, University Abdelmalek Essaadi, Tetouan, Morocco
| | - Randa Yerrou
- ERSN Laboratory, Physics Department, Faculty of Sciences, University Abdelmalek Essaadi, Tetouan, Morocco
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Park M, Yoo J, Kim M, Jang WI, Park S. Determination of counting efficiency considering the biodistribution of 131I activity in the whole-body counting measurement. NUCLEAR ENGINEERING AND TECHNOLOGY 2022. [DOI: 10.1016/j.net.2022.09.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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27
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Subramanian S, He B, Frey E, Jokisch DW, Bolch W, Sgouros G. Improved accuracy of S-value-based dosimetry: a guide to transition from Cristy-Eckerman to ICRP adult phantoms. EJNMMI Phys 2022; 9:57. [PMID: 36018453 PMCID: PMC9418401 DOI: 10.1186/s40658-022-00485-9] [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: 04/13/2022] [Accepted: 08/08/2022] [Indexed: 12/03/2022] Open
Abstract
Background In 2016, the International Commission on Radiological Protection (ICRP) published the results of Monte Carlo simulations performed using updated and anatomically realistic voxelized phantoms. The resulting specific absorbed fractions are based on more realistic human anatomy than those computed in the stylized, geometrical Cristy–Eckerman (CE) phantom. Despite this development, the ICRP-absorbed fractions have not been widely adopted for radiopharmaceutical dosimetry. To help make the transition, we have established a correspondence between source and target tissues defined in the CE phantom and those defined in the ICRP phantoms. Results The ICRP phantom has 79 source regions and 43 target regions in comparison with the 23 source and 18 target tissue regions defined in the CE phantom. The ICRP phantom provides tissue regions with greater anatomical detail. Some of this additional detail is focused on radiation protection and dosimetry of inhaled/ingested radioactivity. Some, but not all, of this detail is useful and appropriate for radiopharmaceutical therapy. We have established the correspondence between CE and ICRP phantom source and target regions and attempted to highlight the ICRP source tissues relevant to radiopharmaceutical therapy (RPT). This paper provides tables and figures highlighting the correspondences established. Conclusion The results provide assistance in transitioning from CE-stylized phantoms to the anatomically accurate voxelized ICRP phantoms. It provides specific guidance for porting the total absorbed activity for regions as defined in the CE phantom to regions within the ICRP phantoms.
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Affiliation(s)
| | - Bin He
- Radiopharmaceutical Imaging and Dosimetry, LLC (Rapid), Baltimore, MD, USA
| | - Eric Frey
- Radiopharmaceutical Imaging and Dosimetry, LLC (Rapid), Baltimore, MD, USA.,The Russell H. Morgan Department of Radiology and Radiological Science, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Derek W Jokisch
- Department of Physics and Engineering, Francis Marion University, Florence, SC, USA.,Center for Radiation Protection Knowledge, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Wesley Bolch
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
| | - George Sgouros
- Radiopharmaceutical Imaging and Dosimetry, LLC (Rapid), Baltimore, MD, USA.,The Russell H. Morgan Department of Radiology and Radiological Science, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
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28
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New thyroid models for ICRP pediatric mesh-type reference computational phantoms. NUCLEAR ENGINEERING AND TECHNOLOGY 2022. [DOI: 10.1016/j.net.2022.08.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
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29
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Gear J. Milestones in dosimetry for nuclear medicine therapy. Br J Radiol 2022; 95:20220056. [PMID: 35451857 PMCID: PMC10996314 DOI: 10.1259/bjr.20220056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 03/31/2022] [Accepted: 04/14/2022] [Indexed: 11/05/2022] Open
Abstract
Nuclear Medicine therapy has reached a critical juncture with an unprecedented number of patients being treated and an extensive list of new radiopharmaceuticals under development. Since the early applications of these treatments dosimetry has played a vital role in their development, in both aiding optimisation and enhancing safety and efficacy. To inform the future direction of this field, it is useful to reflect on the scientific and technological advances that have occurred since those early uses. In this review, we explore how dosimetry has evolved over the years and discuss why such initiatives were conceived and the importance of maintaining standards within our practise. Specific milestones and landmark publications are highlighted and a thematic review and significant outcomes during each decade are presented.
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Affiliation(s)
- Jonathan Gear
- The Joint Department of Physics, The Royal Marsden NHS
Foundation Trust & Institute of Cancer Research,
Sutton, United Kingdom
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30
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Cumur C, Fujibuchi T, Hamada K. Dose estimation for cone-beam computed tomography in image-guided radiation therapy using mesh-type reference computational phantoms and assuming head and neck cancer. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2022; 42:021533. [PMID: 35705020 DOI: 10.1088/1361-6498/ac7914] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 06/15/2022] [Indexed: 06/15/2023]
Abstract
This study aimed to estimate the additional dose the cone-beam computed tomography (CBCT) system integrated into the Varian TrueBeam linear accelerator delivers to a patient with head and neck cancer using mesh-type International Commission on Radiological Protection reference computational phantoms. In the first part, for use as a benchmark for the accuracy of the Monte Carlo geometry of CBCT, Particle and Heavy Ion Transport code System (PHITS) calculations were confirmed against measured lateral and depth dose profiles using a computed tomography dose profiler. After obtaining good agreement, organ dose calculations were performed by PHITS using mesh-type reference computational phantom (MRCP) and irradiating the neck region; the effective dose was calculated utilising absorbed organ doses and tissue weighting factors for male and female MRCP. Substantially, it has been found that the effective doses for male and female MRCP are 0.81 and 1.06 mSv, respectively. As this study aimed to assess the imaging dose from the CBCT system used in image-guided radiation therapy, it is required to take into account this dose in terms of both the target organ and surrounding tissues. Although the absorbed organ dose values and effective dose values obtained for both MRCP males and females were small, attention should be paid to the additional dose resulting from CBCT. This study can create awareness on the importance of doses arising from imaging techniques, especially CBCT.
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Affiliation(s)
- Ceyda Cumur
- Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka City 812-8582, Japan
| | - Toshioh Fujibuchi
- Department of Health Sciences, Faculty of Medical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka City 812-8582, Japan
| | - Keisuke Hamada
- Department of Radiological Technology, National Hospital Organisation Kyushu Cancer Center, 3-1-1, Notame Minami-ku, Fukuoka City 811-1395, Japan
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31
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Avramova-Cholakova S, Dyakov I, Yordanov H, O'Sullivan J. Comparison of patient effective doses from multiple CT examinations based on different calculation methods. Phys Med 2022; 99:73-84. [PMID: 35660792 DOI: 10.1016/j.ejmp.2022.05.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 05/17/2022] [Accepted: 05/25/2022] [Indexed: 11/15/2022] Open
Abstract
The aim of this study is to compare effective dose (E) estimations based on different methods for patients with recurrent computed tomography (CT) examinations. Seventeen methods were used to determine the E of each phase as well as the total E of the CT examination. These included three groups of estimations: based on the use of published E, calculated from typical or patient-specific values of volume computed tomography dose index (CTDIvol) and dose-length product (DLP) multiplied by conversion coefficients, and based on patient-specific calculations with use of software. The E from a single phase of the examination varied with a ratio from 1.3 to 6.8 for small size patients, from 1.2 to 6.5 for normal size patients, and from 1.7 up to 18.1 for large size patients, depending on the calculation method used. The cumulative effective dose (CED) ratio per patient for the different size groups varied as follows: from 1.4 to 2.5 (small), from 1.7 to 4.3 (normal), and from 2.2 up to 6.3 (large). The minimum CED across patients varied from 38 up to 200 mSv, while the variation of maximum CED was from 122 up to 538 mSv. Although E is recommended for population estimations, it is sometimes needed and used for individual patients in clinical practice. Its value is highly dependent on the method applied. Individual estimations of E can vary up to 18.1 times and CED estimations can differ up to 6 times. The related large uncertainties should always be taken into account.
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Affiliation(s)
- Simona Avramova-Cholakova
- Radiological Sciences Unit, Imperial College Healthcare NHS Trust, Fulham Palace Rd, Hammersmith, London W6 8RF, UK.
| | - Iliya Dyakov
- Acibadem City Clinic UMBAL, Tsarigradsko shose 66 A, Sofia 1784, Bulgaria.
| | - Hristomir Yordanov
- Technical University - Sofia, FDIBA, Kliment Ohrisdki blvd 8, 1754 Sofia, Bulgaria.
| | - James O'Sullivan
- Radiological Sciences Unit, Imperial College Healthcare NHS Trust, Fulham Palace Rd, Hammersmith, London W6 8RF, UK. James.O'
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Bauer D, Visca H, Weerakkody A, Carter LM, Samuels Z, Kaminsky S, Andreev OA, Reshetnyak YK, Lewis JS. PET Imaging of Acidic Tumor Environment With 89Zr-labeled pHLIP Probes. Front Oncol 2022; 12:882541. [PMID: 35664740 PMCID: PMC9160799 DOI: 10.3389/fonc.2022.882541] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 04/19/2022] [Indexed: 11/13/2022] Open
Abstract
Acidosis of the tumor microenvironment is a hallmark of tumor progression and has emerged as an essential biomarker for cancer diagnosis, prognosis, and evaluation of treatment response. A tool for quantitatively visualizing the acidic tumor environment could significantly advance our understanding of the behavior of aggressive tumors, improving patient management and outcomes. 89Zr-labeled pH-low insertion peptides (pHLIP) are a class of radiopharmaceutical imaging probes for the in vivo analysis of acidic tumor microenvironments via positron emission tomography (PET). Their unique structure allows them to sense and target acidic cancer cells. In contrast to traditional molecular imaging agents, pHLIP’s mechanism of action is pH-dependent and does not rely on the presence of tumor-specific molecular markers. In this study, one promising acidity-imaging PET probe ([89Zr]Zr-DFO-Cys-Var3) was identified as a candidate for clinical translation.
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Affiliation(s)
- David Bauer
- Department of Radiology and the Molecular Pharmacology Program, Memorial Sloan Kettering Cancer Center, New York, NY, United States
| | - Hannah Visca
- Department of Physics, University of Rhode Island, Kingston, RI, United States
| | - Anuradha Weerakkody
- Department of Physics, University of Rhode Island, Kingston, RI, United States
| | - Lukas M. Carter
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, United States
| | - Zachary Samuels
- Department of Radiology and the Molecular Pharmacology Program, Memorial Sloan Kettering Cancer Center, New York, NY, United States
| | - Spencer Kaminsky
- Department of Radiology and the Molecular Pharmacology Program, Memorial Sloan Kettering Cancer Center, New York, NY, United States
| | - Oleg A. Andreev
- Department of Physics, University of Rhode Island, Kingston, RI, United States
| | - Yana K. Reshetnyak
- Department of Physics, University of Rhode Island, Kingston, RI, United States
| | - Jason S. Lewis
- Department of Radiology and the Molecular Pharmacology Program, Memorial Sloan Kettering Cancer Center, New York, NY, United States
- Department of Radiology, Weill Cornell Medical College, New York, NY, United States
- Department of Pharmacology Program, Weill Cornell Medical College, New York, NY, United States
- *Correspondence: Jason S. Lewis,
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33
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GATE/GEANT4 simulation of radiation risk induced cancer from mammographic screening. Radiat Phys Chem Oxf Engl 1993 2022. [DOI: 10.1016/j.radphyschem.2021.109929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Ku Y, Jung J, Kim CH. New Algorithm to Estimate Proton Beam Range for Multi-slit Prompt-gamma Camera. NUCLEAR ENGINEERING AND TECHNOLOGY 2022. [DOI: 10.1016/j.net.2022.04.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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35
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Dogra P, Ramírez JR, Butner JD, Peláez MJ, Chung C, Hooda-Nehra A, Pasqualini R, Arap W, Cristini V, Calin GA, Ozpolat B, Wang Z. Translational Modeling Identifies Synergy between Nanoparticle-Delivered miRNA-22 and Standard-of-Care Drugs in Triple-Negative Breast Cancer. Pharm Res 2022; 39:511-528. [PMID: 35294699 PMCID: PMC8986735 DOI: 10.1007/s11095-022-03176-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 01/21/2022] [Indexed: 12/29/2022]
Abstract
Purpose Downregulation of miRNA-22 in triple-negative breast cancer (TNBC) is associated with upregulation of eukaryotic elongation 2 factor kinase (eEF2K) protein, which regulates tumor growth, chemoresistance, and tumor immunosurveillance. Moreover, exogenous administration of miRNA-22, loaded in nanoparticles to prevent degradation and improve tumor delivery (termed miRNA-22 nanotherapy), to suppress eEF2K production has shown potential as an investigational therapeutic agent in vivo. Methods To evaluate the translational potential of miRNA-22 nanotherapy, we developed a multiscale mechanistic model, calibrated to published in vivo data and extrapolated to the human scale, to describe and quantify the pharmacokinetics and pharmacodynamics of miRNA-22 in virtual patient populations. Results Our analysis revealed the dose-response relationship, suggested optimal treatment frequency for miRNA-22 nanotherapy, and highlighted key determinants of therapy response, from which combination with immune checkpoint inhibitors was identified as a candidate strategy for improving treatment outcomes. More importantly, drug synergy was identified between miRNA-22 and standard-of-care drugs against TNBC, providing a basis for rational therapeutic combinations for improved response Conclusions The present study highlights the translational potential of miRNA-22 nanotherapy for TNBC in combination with standard-of-care drugs. Supplementary Information The online version contains supplementary material available at 10.1007/s11095-022-03176-3.
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Affiliation(s)
- Prashant Dogra
- Mathematics in Medicine Program, Houston Methodist Research Institute, Houston, Texas, 77030, USA
- Department of Physiology and Biophysics, Weill Cornell Medical College, New York, New York, 10065, USA
| | - Javier Ruiz Ramírez
- Mathematics in Medicine Program, Houston Methodist Research Institute, Houston, Texas, 77030, USA
| | - Joseph D Butner
- Mathematics in Medicine Program, Houston Methodist Research Institute, Houston, Texas, 77030, USA
| | - Maria J Peláez
- Mathematics in Medicine Program, Houston Methodist Research Institute, Houston, Texas, 77030, USA
| | - Caroline Chung
- Department of Radiation Oncology, The University of Texas M.D. Anderson Cancer Center, Houston, Texas, 77030, USA
| | - Anupama Hooda-Nehra
- Rutgers Cancer Institute of New Jersey, Newark, New Jersey, 07101, USA
- Department of Medicine, Division of Hematology/Oncology, Rutgers New Jersey Medical School, Newark, New Jersey, 07103, USA
| | - Renata Pasqualini
- Rutgers Cancer Institute of New Jersey, Newark, New Jersey, 07101, USA
- Department of Radiation Oncology, Division of Cancer Biology, Rutgers New Jersey Medical School, Newark, New Jersey, 07103, USA
| | - Wadih Arap
- Rutgers Cancer Institute of New Jersey, Newark, New Jersey, 07101, USA
- Department of Medicine, Division of Hematology/Oncology, Rutgers New Jersey Medical School, Newark, New Jersey, 07103, USA
| | - Vittorio Cristini
- Mathematics in Medicine Program, Houston Methodist Research Institute, Houston, Texas, 77030, USA
- Department of Imaging Physics, The University of Texas M.D. Anderson Cancer Center, Houston, Texas, 77230, USA
- Physiology, Biophysics, and Systems Biology Program, Graduate School of Medical Sciences, Weill Cornell Medicine, New York, New York, 10065, USA
| | - George A Calin
- Department of Translational Molecular Pathology, The University of Texas M.D. Anderson Cancer Center, Houston, Texas, 77030, USA
| | - Bulent Ozpolat
- Department of Experimental Therapeutics, The University of Texas M.D. Anderson Cancer Center, Houston, Texas, 77030, USA
| | - Zhihui Wang
- Mathematics in Medicine Program, Houston Methodist Research Institute, Houston, Texas, 77030, USA.
- Department of Physiology and Biophysics, Weill Cornell Medical College, New York, New York, 10065, USA.
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36
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Xing S, Shin J, Pursley J, Correa-Alfonso CM, Depauw N, Domal S, Withrow J, Bolch W, Grassberger C, Paganetti H. A dynamic blood flow model to compute absorbed dose to circulating blood and lymphocytes in liver external beam radiotherapy. Phys Med Biol 2022; 67:10.1088/1361-6560/ac4da4. [PMID: 35061601 PMCID: PMC8985306 DOI: 10.1088/1361-6560/ac4da4] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 01/21/2022] [Indexed: 01/01/2023]
Abstract
We have developed a novel 4D dynamic liver blood flow model, capable of accurate dose estimation to circulating blood cells during liver-directed external beam radiotherapy, accounting for blood recirculation and radiation delivery time structure. Adult male and adult female liver computational phantoms with detailed vascular trees were developed to include the hepatic arterial, hepatic portal venous, and hepatic venous trees. A discrete time Markov Chain approach was applied to determine the spatiotemporal distribution of 105blood particles (BP) in the human body based on reference values for cardiac output and organ blood volumes. For BPs entering the liver, an explicit Monte Carlo simulation was implemented to track their propagation along ∼2000 distinct vascular pathways through the liver. The model tracks accumulated absorbed dose from time-dependent radiation fields with a 0.1 s time resolution. The computational model was then evaluated for 3 male and 3 female patients receiving photon (VMAT and IMRT) and proton (passive SOBP and active PBS) treatments. The dosimetric impact of treatment modality, delivery time, and fractionation on circulating blood cells was investigated and quantified using the mean dose (μdose,b),V>0Gy,V>0.125Gy,andD2%. Average reductions inμdose,b,V>0Gy,V>0.125GyandD2%of 45%, 6%, 53%, 19% respectively, were observed for proton treatments as compared to photon treatments. Our simulation also showed thatV>0Gy,V>0.125Gy, andD2%were highly sensitive to the beam-on time. BothV>0GyandV>0.125Gyincreased with beam-on time, whereasD2%decreased with increasing beam-on time, demonstrating the tradeoff between low dose to a large fraction of blood cells and high dose to a small fraction of blood cells. Consequently, proton treatments are not necessarily advantageous in terms of dose to the blood simply based on integral dose considerations. Instead, both integral dose and beam-on time can substantially impact relevant dosimetric indices.
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Affiliation(s)
- Shu Xing
- Massachusetts General Hospital, Harvard Medical school, Boston, MA
| | - Jungwook Shin
- Massachusetts General Hospital, Harvard Medical school, Boston, MA,Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD
| | - Jennifer Pursley
- Massachusetts General Hospital, Harvard Medical school, Boston, MA
| | | | - Nicolas Depauw
- Massachusetts General Hospital, Harvard Medical school, Boston, MA
| | - Sean Domal
- Department of Biomedical Engineering, University of Florida, Gainesville, FL
| | - Julia Withrow
- Department of Biomedical Engineering, University of Florida, Gainesville, FL
| | - Wesley Bolch
- Department of Biomedical Engineering, University of Florida, Gainesville, FL
| | | | - Harald Paganetti
- Massachusetts General Hospital, Harvard Medical school, Boston, MA
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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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38
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Iodine-131 S values for use in organ dose estimation of Korean patients in radioiodine therapy. NUCLEAR ENGINEERING AND TECHNOLOGY 2022. [DOI: 10.1016/j.net.2021.08.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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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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40
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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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Martin CJ, Abuhaimed A, Lee C. Dose quantities for measurement and comparison of doses to individual patients in computed tomography (CT). JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2021; 41:792-808. [PMID: 33690180 DOI: 10.1088/1361-6498/abecf5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 03/09/2021] [Indexed: 06/12/2023]
Abstract
The dose quantities displayed routinely on CT scanners, the volume averaged CT dose index (CTDIvol) and dose length product, provide measures of doses calculated for standard phantoms. The American Association of Medical Physics has published conversion factors for the adjustment of CTDIvolto take account of variations in patient size, the results being termed size-specific dose estimate (SSDE). However, CTDIvoland SSDE, while useful in comparing and optimising doses from a set procedure, do not provide risk-related information that takes account of the organs and tissues irradiated and associated cancer risks. A derivative of effective dose that takes account of differences in body and organ sizes and masses, referred to here as size-specific effective dose (SED), can provide such information. Data on organ doses from NCICT software that is based on Monte Carlo simulations of CT scans for 193 adult phantoms have been used to compute values of SED for CT examinations of the trunk and results compared with corresponding values of SSDE. Relationships within ±8% were observed between SED and SSDE for scans extending over similar regions for phantoms with a wide range of sizes. Coefficients have been derived from fits of the data to estimate SED values from SSDEs for different regions of the body for scans of standard lengths based on patient height. A method developed to take account of differences in scan length gave SED results within ±5% of values calculated using the NCI phantom library. This approach could potentially be used to estimate SED from SSDE values, allowing their display at the time a CT scan is performed.
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Affiliation(s)
- Colin J Martin
- Department of Clinical Physics and Bioengineering, University of Glasgow, Gartnavel Royal Hospital, Glasgow G12 0XH, United Kingdom
| | - Abdullah Abuhaimed
- King Abdulaziz City for Science and Technology (KACST), Riyadh, Saudi Arabia
| | - Choonsik Lee
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD, United States of America
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Mitrovic M, Ciraj-Bjelac O, Jovanovic Z, Krstic N, Nikezic D, Krstic D, Zivkovic M, Lazarevic-Macanovic M. Voxel model of a rabbit: assessment of absorbed doses in organs after CT examination performed by two different protocols. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2021; 60:631-638. [PMID: 34487228 DOI: 10.1007/s00411-021-00941-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Accepted: 08/21/2021] [Indexed: 06/13/2023]
Abstract
The objective of this work was to assess absorbed doses in organs and tissues of a rabbit, following computed tomography (CT) examinations, using a dedicated 3D voxel model. Absorbed doses in relevant organs were calculated using the MCNP5 Monte Carlo software. Calculations were perfomed for two standard CT protocols, using tube voltages of 110 kVp and 130 kVp. Absorbed doses were calculated in 11 organs and tissues, i.e., skin, bones, brain, muscles, heart, lungs, liver, spleen, kidney, testicles, and fat tissue. The doses ranged from 15.3 to 28.3 mGy, and from 40.2 to 74.3 mGy, in the two investigated protocols. The organs that received the highest dose were bones and kidneys. In contrast, brain and spleen were organs that received the smallest doses. Doses in organs which are stretched along the body did not change significantly with distance. On the other hand, doses in organs which are localized in the body showed maximums and minimums. Using the voxel model, it is possible to calculate the dose distribution in the rabbit's body after CT scans, and study the potential biological effects of CT doses in certain organs. The voxel model presented in this work can be used to calculated doses in all radiation experiments in which rabbits are used as experimental animals.
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Affiliation(s)
- M Mitrovic
- Department of Radiology and Radiation Hygiene, Faculty of Veterinary Medicine, University of Belgrade, Belgrade, Serbia
| | - O Ciraj-Bjelac
- Radiation Protection Department, Vinca Institute of Nuclear Sciences, University of Belgrade, Belgrade, Serbia
| | - Z Jovanovic
- Faculty of Science, University of Kragujevac, Kragujevac, Serbia
| | - N Krstic
- Department of Radiology and Radiation Hygiene, Faculty of Veterinary Medicine, University of Belgrade, Belgrade, Serbia
| | - D Nikezic
- State University of Novi Pazar, Novi Pazar, Serbia.
| | - D Krstic
- Faculty of Science, University of Kragujevac, Kragujevac, Serbia
| | - M Zivkovic
- Faculty of Science, University of Kragujevac, Kragujevac, Serbia
| | - M Lazarevic-Macanovic
- Department of Radiology and Radiation Hygiene, Faculty of Veterinary Medicine, University of Belgrade, Belgrade, Serbia
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43
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Carter LM, Ocampo Ramos JC, Kesner AL. Personalized dosimetry of 177Lu-DOTATATE: a comparison of organ- and voxel-level approaches using open-access images. Biomed Phys Eng Express 2021; 7. [PMID: 34271565 DOI: 10.1088/2057-1976/ac1550] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 07/16/2021] [Indexed: 11/11/2022]
Abstract
177Lu-DOTATATE (Lutathera®) enables targeted radionuclide therapy of neuroendocrine tumors expressing somatostatin receptor type 2. Though patient-specific dosimetry estimates may be clinically important for predicting absorbed dose-effect relationships, there are multiple relevant dosimetry paradigms which are distinct in terms of clinical effort, numerical output and added-value. This work compares three different approaches for177Lu-DOTATATE dosimetry, including 1) an organ-level approach based on reference phantom MIRD S-values scaled to patient-specific organ masses (MIRDcalc), 2) an organ-level approach based on Monte Carlo simulation in a patient-specific mesh phantoms (PARaDIM), and 3) a 3D approach based on Monte Carlo simulation in patient-specific voxel phantoms.Method. Serial quantitative SPECT/CT images for two patients receiving177Lu-DOTATATE therapy were obtained from archive in theDeep Bluedatabase. For each patient, the serial CT images were co-registered to the first time point CT using a deformable registration technique aided by virtual landmarks placed in the kidney pelves and the lesion foci. The co-registered SPECT images were integrated voxel-wise to generate time-integrated activity maps. Lesions, kidneys, liver, spleen, lungs, compact bone, spongiosa, and rest of body were segmented at the first imaging time point and overlaid on co-registered integrated activity maps. The resultant segmentation was used for three purposes: 1) to generate patient-specific phantoms, 2) to determine organ-level time-integrated activities, and 3) to generate dose volume histograms from 3D voxel-based calculations.Results. Mean absorbed doses were computed for lesions and 48 tissues with MIRDcalc software. Mean organ absorbed doses and dose volume histograms were obtained for lesions and 6 tissues with the voxel Monte Carlo approach. Lesion- and organ-level absorbed dose estimates agreed within ±26% for the lesions and ±13% for the critical organs, among the different methods tested. Overall good agreement was observed with the dosimetry estimates from the NETTER-1 trial.Conclusions. For personalized177Lu-DOTATATE dosimetry, a combined approach was determined to be valuable, which utilized two dose calculation methods supported by a single image processing workflow. In the absence of quantitative imaging limitations, the voxel Monte Carlo method likely provides valuable information to guide treatment by considering absorbed dose non-uniformity in lesions and organs at risk. The patient-scaled reference phantom method also provides valuable information, including absorbed dose estimates for non-segmented organs, and more accurate dose estimates for complex radiosensitive organs including the active marrow.
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Affiliation(s)
- L M Carter
- Deparment of Medical Physics, Memorial Sloan Kettering Cancer Center, NY, 10065, United States of America
| | - J C Ocampo Ramos
- Deparment of Medical Physics, Memorial Sloan Kettering Cancer Center, NY, 10065, United States of America
| | - A L Kesner
- Deparment of Medical Physics, Memorial Sloan Kettering Cancer Center, NY, 10065, United States of America
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Shin J, Xing S, McCullum L, Hammi A, Pursley J, Correa CA, Withrow J, Domal S, Bolch W, Paganetti H, Grassberger C. HEDOS-a computational tool to assess radiation dose to circulating blood cells during external beam radiotherapy based on whole-body blood flow simulations. Phys Med Biol 2021; 66:10.1088/1361-6560/ac16ea. [PMID: 34293735 PMCID: PMC8720566 DOI: 10.1088/1361-6560/ac16ea] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 07/22/2021] [Indexed: 11/11/2022]
Abstract
We have developed a time-dependent computational framework, hematological dose (HEDOS), to estimate dose to circulating blood cells from radiation therapy treatment fields for any treatment site. Two independent dynamic models were implemented in HEDOS: one describing the spatiotemporal distribution of blood particles (BPs) in organs and the second describing the time-dependent radiation field delivery. A whole-body blood flow network based on blood volumes and flow rates from ICRP Publication 89 was simulated to produce the spatiotemporal distribution of BPs in organs across the entire body using a discrete-time Markov process. Constant or time-varying transition probabilities were applied and their impact on transition time was investigated. The impact of treatment time and anatomical site were investigated using imaging data and dose distributions from a liver cancer and a brain cancer patient. The simulations revealed different dose levels to the circulating blood for brain irradiation compared to liver irradiation even for similar field sizes due to the different blood flow properties of the two organs. The volume of blood receiving any dose (V>0 Gy) after a single radiation fraction increases from 1.2% for a 1 s delivery time to 20.9% for 120 s delivery time for the brain cancer treatment, and from 10% (1 s) to 48.7% (120 s) for a liver cancer treatment. Other measures of the low-dose bath to the circulating blood such as the dose to small volumes of blood (D2%) decreases with longer delivery time. Furthermore, we demonstrate that the blood dose-volume histogram is highly sensitive to changes in the treatment time, indicating that dynamic modeling of blood flow and radiation fields is necessary to evaluate dose to circulating blood cells for the assessment of radiation-induced lymphopenia. HEDOS is publicly available and allows for the estimation of patient-specific dose to circulating blood cells based on organ DVHs, thus enabling the study of the impact of different treatment plans, dose rates, and fractionation schemes.
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Affiliation(s)
- Jungwook Shin
- Division of Radiation Biophysics, Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States of America
| | - Shu Xing
- Division of Radiation Biophysics, Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States of America
| | - Lucas McCullum
- Division of Radiation Biophysics, Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States of America
| | - Abdelkhalek Hammi
- Division of Radiation Biophysics, Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States of America
| | - Jennifer Pursley
- Division of Radiation Biophysics, Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States of America
| | - Camilo A Correa
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, United States of America
| | - Julia Withrow
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, United States of America
| | - Sean Domal
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, United States of America
| | - Wesley Bolch
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, United States of America
| | - Harald Paganetti
- Division of Radiation Biophysics, Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States of America
| | - Clemens Grassberger
- Division of Radiation Biophysics, Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States of America
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Rosenstrom A, Asano E, Griffin K, Lee C, Hooper D, Dewji S. Dose Coefficient Calculation for Use in Dosimetry Assessment of a Fission-Based Weapon. Radiat Res 2021; 196:272-283. [PMID: 34237146 DOI: 10.1667/rade-21-00012.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 06/03/2021] [Indexed: 11/03/2022]
Abstract
In the event of a fission-based weapon or improvised nuclear device (IND) detonation, dose coefficients can be harnessed to provide dose assessments for defense, emergency preparedness, and consequence management, as well as to prospectively inform the assessment of radiation biomarkers and development of medical prophylaxis countermeasures for defense and homeland security stakeholders and decision-makers. Although dose coefficients have previously been calculated for this group, they would apply specifically to the studied population, the 1945 Japanese cohort, after which their anthropomorphic computational phantoms were modeled. For this reason, applications to other populations may be limited, and instead, an assessment of a more standardized population is desired. We employed a series of computational human phantoms representing international reference individuals: UF/NCI voxel phantom series containing newborn, 1-, 5-, 10-, 15-, and 35-year-old males and females. Irradiation of the phantoms was simulated using the Monte Carlo N-Particle transport code to determine organ dose coefficients under four idealized irradiation geometries at three distances from the detonation hypocenter at Hiroshima and Nagasaki using DS02 free-in-air prompt neutron and photon fluence spectra. Through these simulations, age-specific dose coefficients were determined for individual organs. Various articulated PIMAL stylized phantoms were simulated as well, to estimate the effect of body posture on dose coefficients and determine the effect of posture on dosimetric estimation and reconstruction. Results additionally demonstrate that that 137Cs and the Watt fission spectrum are not ideal general surrogate sources for fission weapons, which may be considered for experimental testing of medical countermeasures. Supplementary data provided tabulates the culmination of organ dose-rate coefficients in this study.
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Affiliation(s)
- Andrew Rosenstrom
- Department of Nuclear Engineering, Center for Nuclear Security Science and Policy Initiatives Texas A&M University, College Station, Texas 77843-3133
| | - Ethan Asano
- Department of Nuclear Engineering, Center for Nuclear Security Science and Policy Initiatives Texas A&M University, College Station, Texas 77843-3133
| | - Keith Griffin
- National Cancer Institute, Rockville, Maryland 20850
| | - Choonsik Lee
- National Cancer Institute, Rockville, Maryland 20850
| | - David Hooper
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830
| | - Shaheen Dewji
- Department of Nuclear Engineering, Center for Nuclear Security Science and Policy Initiatives Texas A&M University, College Station, Texas 77843-3133
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46
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Carter LM, Choi C, Krebs S, Beattie BJ, Kim CH, Schoder H, Bolch WE, Kesner AL. Patient Size-Dependent Dosimetry Methodology Applied to 18F-FDG Using New ICRP Mesh Phantoms. J Nucl Med 2021; 62:jnumed.120.256719. [PMID: 33863823 PMCID: PMC8612182 DOI: 10.2967/jnumed.120.256719] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 03/16/2021] [Accepted: 03/16/2021] [Indexed: 11/16/2022] Open
Abstract
Despite the known influence of anatomic variability on internal dosimetry, dosimetry for 18F-FDG and other diagnostic radiopharmaceuticals is routinely derived using reference phantoms, which embody population-averaged morphometry for a given age and sex. Moreover, phantom format affects dosimetry estimates to varying extent. Here, we applied newly developed mesh format reference phantoms and a patient-dependent phantom library to assess the impact of height, weight, and body contour variation on dosimetry of 18F-FDG. We compared the mesh reference phantom dosimetry estimates with corresponding estimates from common software to identify differences related to phantom format or software implementation. Our study serves as an example of how more precise patient size-dependent dosimetry methodology could be performed. Methods: Absorbed dose coefficients were computed for the adult mesh reference phantoms and derivative patient-dependent phantom series by Monte Carlo simulation using the PHITS radiation transport code within PARaDIM software. The dose coefficients were compared with reference absorbed dose coefficients obtained from ICRP Publication 128, or generated using software including OLINDA 2.1, OLINDA 1.1, and IDAC-dose 2.1. Results: Differences in dosimetry arising from anatomical variations were shown to be significant, with detriment-weighted dose coefficients for the percentile-specific phantoms varying by up to ±40% relative to the corresponding reference phantom effective dose coefficients, irrespective of phantom format. Similar variations were seen in the individual organ absorbed dose coefficients for the percentile-specific phantoms relative to the reference phantoms. The effective dose coefficient for the mesh reference adult was 0.017 mSv/MBq, which was 5% higher than estimated by a corresponding voxel phantom, and 10% lower than estimated by the stylized phantom format. Conclusion: We observed notable variability in 18F-FDG dosimetry across morphometrically different patients, supporting the use of patient-dependent phantoms for more accurate dosimetric estimations relative to standard reference dosimetry. These data may help in optimizing imaging protocols and research studies, in particular when longer-lived isotopes are employed.
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Affiliation(s)
- Lukas M. Carter
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Chansoo Choi
- Department of Nuclear Engineering, Hanyang University, Seoul, Republic of Korea
| | - Simone Krebs
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York; and
| | - Bradley J. Beattie
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Chan Hyeong Kim
- Department of Nuclear Engineering, Hanyang University, Seoul, Republic of Korea
| | - Heiko Schoder
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York; and
| | - Wesley E. Bolch
- J. Crayton Pruitt Department of Biomedical Engineering, University of Florida, Gainesville, Florida
| | - Adam L. Kesner
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York
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47
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Martin CJ, Harrison JD, Rehani MM. Effective dose from radiation exposure in medicine: Past, present, and future. Phys Med 2020; 79:87-92. [DOI: 10.1016/j.ejmp.2020.10.020] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Revised: 10/18/2020] [Accepted: 10/23/2020] [Indexed: 01/20/2023] Open
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