Abstract
The objective of this study is to develop a skeleton model for assessing active marrow dose from bone-seeking beta-emitting radionuclides. This article explains the modeling methodology which accounts for individual variability of the macro- and microstructure of bone tissue. Bone sites with active hematopoiesis are assessed by dividing them into small segments described by simple geometric shapes. Spongiosa, which fills the segments, is modeled as an isotropic three-dimensional grid (framework) of rod-like trabeculae that "run through" the bone marrow. Randomized multiple framework deformations are simulated by changing the positions of the grid nodes and the thickness of the rods. Model grid parameters are selected in accordance with the parameters of spongiosa microstructures taken from the published papers. Stochastic modeling of radiation transport in heterogeneous media simulating the distribution of bone tissue and marrow in each of the segments is performed by Monte Carlo methods. Model output for the human femur at different ages is provided as an example. The uncertainty of dosimetric characteristics associated with individual variability of bone structure was evaluated. An advantage of this methodology for the calculation of doses absorbed in the marrow from bone-seeking radionuclides is that it does not require additional studies of autopsy material. The biokinetic model results will be used in the future to calculate individual doses to members of a cohort exposed to 89,90Sr from liquid radioactive waste discharged to the Techa River by the Mayak Production Association in 1949-1956. Further study of these unique cohorts provides an opportunity to gain more in-depth knowledge about the effects of chronic radiation on the hematopoietic system. In addition, the proposed model can be used to assess the doses to active marrow under any other scenarios of 90Sr and 89Sr intake to humans.
Highlights
Environmental radioactive contamination in the Southern Urals from Mayak plutonium facility releases in the 1950s led to substantial doses to the residents of nearby communities, and, subsequently, to health effects [1,2,3,4,5,6]
The current paper presents a general description of the voxel-based Stochastic Parametric Skeletal Dosimetry (SPSD) model for humans, originally proposed by E
To lead off the discussion, the reader is reminded of three important aspects of this study: (1) the motivation of the study was to improve estimates of radiation risk of leukemia in the Techa
Summary
Environmental radioactive contamination in the Southern Urals from Mayak plutonium facility releases in the 1950s led to substantial doses to the residents of nearby communities, and, subsequently, to health effects [1,2,3,4,5,6]. The method allows for the study of a larger volume of spongiosa samples, and a quick evaluation of parameters (regardless of the rod or plate trabecular model); the measurement results significantly depend on microCT resolution [35, 36]. In the current study both microCT imaging with adequate resolution ( 40 μm) as well as histomorphometry data obtained using the rod trabecular model are considered for the assessment of bone parameters. The dosimetry problem is to evaluate energy deposition in target regions for particles emitted in TBV and CBV sources This problem can be solved by stochastic modeling of radiation transport in a porous structure simulating the spatial distribution of bone and marrow within spongiosa.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
