Anatomical and Morphological Basis for Dosimetric Modeling of Human Trabecular Bone Using a Stochastic Parametric Approach
Authors:   Urals Research Center for Radiation Medicine FMBA of Russia, Chelyabinsk, Tolstykh E.I. , Sharagin P.A. ,   Urals Research Center for Radiation Medicine FMBA of Russia, Chelyabinsk, Shishkina E.A. ,   Urals Research Center for Radiation Medicine FMBA of Russia, Chelyabinsk,   Chelyabinsk State University, Chelyabinsk, Russia, Volchkova A.Yu. ,   Urals Research Center for Radiation Medicine FMBA of Russia, Chelyabinsk, Degteva M.O. ,   Urals Research Center for Radiation Medicine FMBA of Russia, Chelyabinsk
Published: October 2022

Purpose: To create an anatomical and morphological basis for a Stochastic Parametric Skeletal Dosimetric model (SPSDmodel) for a human of different age, which includes an assessment of the parameters of the trabecular bone microstructure in the hematopoietic regions of the human skeleton. The model is necessary to estimate the doses to red bone marrow from osteotropic radionuclides (89,90Sr). The model is being created as a part of the dosimetric support for epidemiological studies of the South Ural cohorts, the members of which lived in territories radioactively contaminated in the 1950s. Materials and methods: Estimation of model parameters is based on the collection and analysis of published data. The selection of publications was made using Internet search engines: Google, PubMed, Academia, e-library, etc. Original articles in peerreviewed publications were selected, atlases, manuals, monographs and dissertations were considered. Information was collected only on healthy individuals. The collected data reffered to the following parameters of the trabecular bone: trabecular thickness, intertrabecular space, the proportion of bone in the total tissue volume. The parameters were assessed using histomorphometry and micro-CT. To make a decision about bone modeling, the data on a hematopoietic activity in it, obtained by MRI and PET, were considered. Result: Based on the results of the analysis of published information, primary data files were generated containing bibliographic data on the source of information, data on the subjects of the study and the measurement results of trabecular bone parameters. On this basis, average population estimates of the parameters were obtained and their variability (standard deviation, coefficients of variation) was estimated. Data on the duration of hematopoiesis in various parts of the skeleton and data on age-related changes in the microstructure were analyzed. The paper presents a description of a full set of parameters of the SPSD model of trabecular bones for newborns, children aged 1, 5 and 10 years, as well as for adolescents aged 15 years and adults. Conclusion: The obtained numerical values are used as input data (parameters) for generating dosimetric phantoms in voxel form. Our results will make it possible in the future to calculate conversion factors that relate the specific activity of radionuclides in the source tissue (bone trabeculae) to the dose rate in the detector tissue (red bone marrow), as well as the uncertainty of their estimates.