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Calculation of S-values for Technetium-99m in the DIGIMOUSE voxel phantom using Monte Carlo simulations. Radiat Phys Chem Oxf Engl 1993 2022. [DOI: 10.1016/j.radphyschem.2022.110151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Zhang X, Qu D, Ji Y, Xie X, Ning J. Study of rat organ dose conversion coefficients for external photon irradiation based on voxel model and Monte Carlo simulation. Appl Radiat Isot 2020; 156:109008. [DOI: 10.1016/j.apradiso.2019.109008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Revised: 11/03/2019] [Accepted: 11/23/2019] [Indexed: 10/25/2022]
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Locatelli M, Miloudi H, Autret G, Balvay D, Desbrée A, Blanchardon E, Bertho JM. RODES software for dose assessment of rats and mice contaminated with radionuclides. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2017; 37:214-229. [PMID: 28141579 DOI: 10.1088/1361-6498/aa58aa] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
In order to support animal experiments of chronic radionuclides intake with realistic dosimetry, voxel-based three-dimensional computer models of mice and rats of both sexes and three ages were built from magnetic resonance imaging. Radiation transport of mono-energetic photons of 11 energies and electrons of 7 energies was simulated with MCNPX 2.6c to assess specific absorbed fractions (SAFs) of energy emitted from 13 source regions and absorbed in 28 target regions. RODES software was developed to combine SAF with radiation emission spectra and user-supplied biokinetic data to calculate organ absorbed doses per nuclear transformation of radionuclides in source regions (S-factors) and for specific animal experiments with radionuclides. This article presents the design of RODES software including the simulation of the particles in the created rodent voxel phantoms. SAF and S-factor values were compared favourably with published results from similar studies. The results are discussed for rodents of different ages and sexes.
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Affiliation(s)
- Maxime Locatelli
- INSERM U970, PARCC-HEGP, Plateforme Imageries du Vivant, Université Paris Descartes-Sorbonne Paris Cité, Paris, France
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Mendes BM, Almeida IGD, Trindade BM, Fonseca TCF, Campos TPRD. Development of a mouse computational model for MCNPx based on Digimouse (r) images and dosimetric assays. BRAZ J PHARM SCI 2017. [DOI: 10.1590/s2175-97902017000116092] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
- Bruno Melo Mendes
- Centro de Desenvolvimento da Tecnologia Nuclear, Brasil; Universidade Federal de Minas Gerais, Brazil
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Sinha A, Patni HK, Dixit BM, Painuly NK, Singh N. Estimation of Photon Specific Absorbed Fractions in Digimouse Voxel Phantom using Monte Carlo Simulation Code FLUKA. J Biomed Phys Eng 2016; 6:209-216. [PMID: 28144589 PMCID: PMC5219571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 08/25/2015] [Indexed: 06/06/2023]
Abstract
BACKGROUND Most preclinical studies are carried out on mice. For internal dose assessment of a mouse, specific absorbed fraction (SAF) values play an important role. In most studies, SAF values are estimated using older standard human organ compositions and values for limited source target pairs. OBJECTIVE SAF values for monoenergetic photons of energies 15, 50, 100, 500, 1000 and 4000 keV were evaluated for the Digimouse voxel phantom incorporated in Monte Carlo code FLUKA. The organ sources considered in this study were lungs, skeleton, heart, bladder, testis, stomach, spleen, pancreas, liver, kidney, adrenal, eye and brain. The considered target organs were lungs, skeleton, heart, bladder, testis, stomach, spleen, pancreas, liver, kidney, adrenal and brain. Eye was considered as a target organ only for eye as a source organ. Organ compositions and densities were adopted from International Commission on Radiological Protection (ICRP) publication number 110. RESULTS Evaluated organ masses and SAF values are presented in tabular form. It is observed that SAF values decrease with increasing the source-to-target distance. The SAF value for self-irradiation decreases with increasing photon energy. The SAF values are also found to be dependent on the mass of target in such a way that higher values are obtained for lower masses. The effect of composition is highest in case of target organ lungs where mass and estimated SAF values are found to have larger differences. CONCLUSION These SAF values are very important for absorbed dose calculation for various organs of a mouse.
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Affiliation(s)
- A Sinha
- Faculty of Physical Sciences, Shri Ramswaroop Memorial University, Lucknow, India
| | - H K Patni
- Bhabha Atomic Research Center, Mumbai, India
| | - B M Dixit
- Faculty of Physical Sciences, Shri Ramswaroop Memorial University, Lucknow, India
| | - N K Painuly
- Department of Radiotherapy, King George Medical University, Lucknow, India
| | - N Singh
- Department of Radiotherapy, King George Medical University, Lucknow, India
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Xie T, Zaidi H. Development of computational small animal models and their applications in preclinical imaging and therapy research. Med Phys 2016; 43:111. [PMID: 26745904 DOI: 10.1118/1.4937598] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The development of multimodality preclinical imaging techniques and the rapid growth of realistic computer simulation tools have promoted the construction and application of computational laboratory animal models in preclinical research. Since the early 1990s, over 120 realistic computational animal models have been reported in the literature and used as surrogates to characterize the anatomy of actual animals for the simulation of preclinical studies involving the use of bioluminescence tomography, fluorescence molecular tomography, positron emission tomography, single-photon emission computed tomography, microcomputed tomography, magnetic resonance imaging, and optical imaging. Other applications include electromagnetic field simulation, ionizing and nonionizing radiation dosimetry, and the development and evaluation of new methodologies for multimodality image coregistration, segmentation, and reconstruction of small animal images. This paper provides a comprehensive review of the history and fundamental technologies used for the development of computational small animal models with a particular focus on their application in preclinical imaging as well as nonionizing and ionizing radiation dosimetry calculations. An overview of the overall process involved in the design of these models, including the fundamental elements used for the construction of different types of computational models, the identification of original anatomical data, the simulation tools used for solving various computational problems, and the applications of computational animal models in preclinical research. The authors also analyze the characteristics of categories of computational models (stylized, voxel-based, and boundary representation) and discuss the technical challenges faced at the present time as well as research needs in the future.
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Affiliation(s)
- Tianwu Xie
- Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, Geneva 4 CH-1211, Switzerland
| | - Habib Zaidi
- Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, Geneva 4 CH-1211, Switzerland; Geneva Neuroscience Center, Geneva University, Geneva CH-1205, Switzerland; and Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen 9700 RB, The Netherlands
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Kostou T, Papadimitroulas P, Loudos G, Kagadis GC. A preclinical simulated dataset ofS-values and investigation of the impact of rescaled organ masses using the MOBY phantom. Phys Med Biol 2016; 61:2333-55. [DOI: 10.1088/0031-9155/61/6/2333] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Martinez NE, Johnson TE, Pinder JE. Application of computational models to estimate organ radiation dose in rainbow trout from uptake of molybdenum-99 with comparison to iodine-131. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2016; 151 Pt 2:468-479. [PMID: 26048012 DOI: 10.1016/j.jenvrad.2015.05.021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2014] [Revised: 05/20/2015] [Accepted: 05/24/2015] [Indexed: 06/04/2023]
Abstract
This study compares three anatomical phantoms for rainbow trout (Oncorhynchus mykiss) for the purpose of estimating organ radiation dose and dose rates from molybdenum-99 ((99)Mo) uptake in the liver and GI tract. Model comparison and refinement is important to the process of determining accurate doses and dose rates to the whole body and the various organs. Accurate and consistent dosimetry is crucial to the determination of appropriate dose-effect relationships for use in environmental risk assessment. The computational phantoms considered are (1) a geometrically defined model employing anatomically relevant organ size and location, (2) voxel reconstruction of internal anatomy obtained from CT imaging, and (3) a new model utilizing NURBS surfaces to refine the model in (2). Dose Conversion Factors (DCFs) for whole body as well as selected organs of O. mykiss were computed using Monte Carlo modeling and combined with empirical models for predicting activity concentration to estimate dose rates and ultimately determine cumulative radiation dose (μGy) to selected organs after several half-lives of (99)Mo. The computational models provided similar results, especially for organs that were both the source and target of radiation (less than 30% difference between all models). Values in the empirical model as well as the 14 day cumulative organ doses determined from (99)Mo uptake are compared to similar models developed previously for (131)I. Finally, consideration is given to treating the GI tract as a solid organ compared to partitioning it into gut contents and GI wall, which resulted in an order of magnitude difference in estimated dose for most organs.
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Affiliation(s)
- N E Martinez
- Department of Environmental Engineering and Earth Sciences, Clemson University, 342 Computer Ct, Anderson, SC 29625, USA.
| | - T E Johnson
- Department of Environmental and Radiological Health Sciences, Colorado State University, 1681 Campus Delivery, Fort Collins, CO, 80523, USA
| | - J E Pinder
- Department of Environmental and Radiological Health Sciences, Colorado State University, 1681 Campus Delivery, Fort Collins, CO, 80523, USA
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Welch D, Harken AD, Randers-Pehrson G, Brenner DJ. Construction of mouse phantoms from segmented CT scan data for radiation dosimetry studies. Phys Med Biol 2015; 60:3589-98. [PMID: 25860401 DOI: 10.1088/0031-9155/60/9/3589] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We present the complete construction methodology for an anatomically accurate mouse phantom made using materials which mimic the characteristics of tissue, lung, and bone for radiation dosimetry studies. Phantoms were constructed using 2 mm thick slices of tissue equivalent material which was precision machined to clear regions for insertion of lung and bone equivalent material where appropriate. Images obtained using a 3D computed tomography (CT) scan clearly indicate regions of tissue, lung, and bone that match their position within the original mouse CT scan. Additionally, radiographic films are used with the phantom to demonstrate dose mapping capabilities. The construction methodology presented here can be quickly and easily adapted to create a phantom of any specific small animal given a segmented CT scan of the animal. These physical phantoms are a useful tool to examine individual organ dose and dosimetry within mouse systems that are complicated by density inhomogeneity due to bone and lung regions.
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Affiliation(s)
- D Welch
- Center for Radiological Research, Columbia University, 630 West 168th Street, New York, NY, USA
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Li D, Chen B, Ran WY, Wang GX, Wu WJ. Selection of voxel size and photon number in voxel-based Monte Carlo method: criteria and applications. JOURNAL OF BIOMEDICAL OPTICS 2015; 20:095014. [PMID: 26417866 DOI: 10.1117/1.jbo.20.9.095014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Accepted: 08/31/2015] [Indexed: 05/27/2023]
Abstract
The voxel-based Monte Carlo method (VMC) is now a gold standard in the simulation of light propagation in turbid media. For complex tissue structures, however, the computational cost will be higher when small voxels are used to improve smoothness of tissue interface and a large number of photons are used to obtain accurate results. To reduce computational cost, criteria were proposed to determine the voxel size and photon number in 3-dimensional VMC simulations with acceptable accuracy and computation time. The selection of the voxel size can be expressed as a function of tissue geometry and optical properties. The photon number should be at least 5 times the total voxel number. These criteria are further applied in developing a photon ray splitting scheme of local grid refinement technique to reduce computational cost of a nonuniform tissue structure with significantly varying optical properties. In the proposed technique, a nonuniform refined grid system is used, where fine grids are used for the tissue with high absorption and complex geometry, and coarse grids are used for the other part. In this technique, the total photon number is selected based on the voxel size of the coarse grid. Furthermore, the photon-splitting scheme is developed to satisfy the statistical accuracy requirement for the dense grid area. Result shows that local grid refinement technique photon ray splitting scheme can accelerate the computation by 7.6 times (reduce time consumption from 17.5 to 2.3 h) in the simulation of laser light energy deposition in skin tissue that contains port wine stain lesions.
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Affiliation(s)
- Dong Li
- Xi'an Jiaotong University, State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an 710049, China
| | - Bin Chen
- Xi'an Jiaotong University, State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an 710049, China
| | - Wei Yu Ran
- Xi'an Jiaotong University, State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an 710049, China
| | - Guo Xiang Wang
- Xi'an Jiaotong University, State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an 710049, ChinabUniversity of Akron, Department of Mechanical Engineering, Akron, Ohio 44325-3903, United States
| | - Wen Juan Wu
- Xi'an Jiaotong University, State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an 710049, China
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Mauxion T, Barbet J, Suhard J, Pouget JP, Poirot M, Bardiès M. Improved realism of hybrid mouse models may not be sufficient to generate reference dosimetric data. Med Phys 2013; 40:052501. [DOI: 10.1118/1.4800801] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Mohammadi A, Kinase S, Saito K. Evaluation of absorbed doses in voxel-based and simplified models for small animals. RADIATION PROTECTION DOSIMETRY 2012; 150:283-291. [PMID: 22171096 DOI: 10.1093/rpd/ncr419] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Internal dosimetry in non-human biota is desirable from the viewpoint of radiation protection of the environment. The International Commission on Radiological Protection (ICRP) proposed Reference Animals and Plants using simplified models, such as ellipsoids and spheres and calculated absorbed fractions (AFs) for whole bodies. In this study, photon and electron AFs in whole bodies of voxel-based rat and frog models have been calculated and compared with AFs in the reference models. It was found that the voxel-based and the reference frog (or rat) models can be consistent for the whole-body AFs within a discrepancy of 25%, as the source was uniformly distributed in the whole body. The specific absorbed fractions (SAFs) and S values were also evaluated in whole bodies and all organs of the voxel-based frog and rat models as the source was distributed in the whole body or skeleton. The results demonstrated that the whole-body SAFs reflect SAFs of all individual organs as the source was uniformly distributed per mass within the whole body by about 30% uncertainties with exceptions for body contour (up to -40%) for both electrons and photons due to enhanced radiation leakages, and for the skeleton for photons only (up to +185%) due to differences in the mass attenuation coefficients. For nuclides such as (90)Y and (90)Sr, which were concentrated in the skeleton, there were large differences between S values in the whole body and those in individual organs, however the whole-body S values for the reference models with the whole body as the source were remarkably similar to those for the voxel-based models with the skeleton as the source, within about 4 and 0.3%, respectively. It can be stated that whole-body SAFs or S values in simplified models without internal organs are not sufficient for accurate internal dosimetry because they do not reflect SAFs or S values of all individual organs as the source was not distributed uniformly in whole body. Thus, voxel-based models would be good candidates for dosimetry in non-human biota if further accuracy in environmental dosimetry is desired.
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Affiliation(s)
- Akram Mohammadi
- Medical Radioisotope Application Group, Japan Atomic Energy Agency (JAEA), 2-4 Shirakata, Shirane, Tokai-mura, Naka-gun, Ibaraki 319-1195, Japan.
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