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Domal, S. J.*; Correa-Alfonso, C. M.*; Paulbeck, C. J.*; Griffin, K. T.*; Sato, Tatsuhiko; Funamoto, Sachiyo*; Cullings, H. M.*; Egbert, S. D.*; Endo, Akira; Hertel, N. E.*; et al.
Health Physics, 125(4), p.245 - 259, 2023/10
Times Cited Count：0 Percentile：0.01(Environmental Sciences)The RERF Working Group on Organ Dose (WGOD) has established the J45 (Japan 1945) series of high-resolution voxel phantoms, which were derived from the UF/NCI series of hybrid phantoms and scaled to match mid-1940s Japanese body morphometries. In this present study, we present the J45 pregnant female phantoms in both a kneeling and lying posture, and assess the dosimetric impact of these more anatomically realistic survivor models in comparisons to current organ doses given by the DS02 system. For the kneeling phantoms facing the bomb hypocenter, organ doses from bomb source photon spectra were shown to be overestimated by the DS02 system by up to a factor of 1.45 for certain fetal organs and up to a factor of 1.17 for maternal organs. For lying phantoms with their feet in the direction of the hypocenter, fetal organ doses from bomb source photon spectra were underestimated by the DS02 system by factors as low as 0.77 while maternal organ doses were overestimated by up to a factor of 1.38. Results from this study highlight the degree to which the existing DS02 system can differ from organ dosimetry based upon 3D radiation transport simulations using more anatomically realistic models of those survivors exposed during pregnancy while in a kneeling or lying position.
Furuta, Takuya; El Basha, D.*; Iyer, S. S. R.*; Correa Alfonso, C. M.*; Bolch, W. E.*
Journal of Radiological Protection, 39(3), p.825 - 837, 2019/09
Times Cited Count：2 Percentile：21.58(Environmental Sciences)Despite large variation of human eye, only one computational eye model has been adopted in almost all the radiation transport simulation studies. We thus adopted a new scalable and deformable eye model and studied the radiation exposure by electrons, photons, and neutrons in the standard radiation fields such as AP, PA, RLAT, ROT, by using Monte Carlo radiation transport code PHITS. We computed the radiation exposure for 5 eye models (standard, large, small, myopic, hyperopic) and analyzed influence of absorbed dose in ocular structures on eye size and shape. Dose distribution of electrons is conformal and therefore the absorbed doses in ocular structures depend on the depth location of each ocular structure. We thus found a significant variation of the absorbed doses for each ocular structure for electron exposure due to change of the depth location affected by eye size and shape. On the other hand only small variation was observed for photons and neutrons exposures because of less conformal dose distribution of those particles.
Furuta, Takuya; El Basha, D.*; Iyer, S. S. R.*; Correa Alfonso, C. M.*; Bolch, W. E.*
no journal, ,
With recent changes in the recommended annual dose limit on eye lens by International Commission on Radiological Protection, there is considerable interest in assessment of radiation exposure on eyes. Several Monte Carlo studies has been performed using a computational eye model. Although there are a large variety in size and shape for individual eyes, the eye model of one standard eye size and shape was adopted in most of those studies. We therefore constructed a geometric eye model that is both scalable (allowing for changes in eye size) and deformable (allowing for changes in eye shape), and studied dosimetry influence on the variation of the eye size and shape in the standard ICRP radiation geometries. We confirmed that only a trivial dependence on the eye size and shape, namely variation of the depth location of the ocular structures, was observed for radiation exposure in the broad radiation geometries.
Furuta, Takuya; El Basha, D.*; Iyer, S. S. R.*; Correa Alfonso, C. M.*; Bolch, W. E.*
no journal, ,
With recent changes in the recommended annual dose limit on eye lens by International Commission on Radiological Protection, several Monte Carlo studies has been performed using a computational eye model. Although there are a large variety in size and shape for individual eyes, the eye model of one standard eye size and shape was adopted in most of those studies. We therefore constructed a geometric eye model that is both scalable and deformable, and studied dosimetry influence on the variation of the eye size and shape in the standard radiation geometries using Monte Carlo radiation transport code PHITS. We confirmed that only a trivial dependence on the eye size and shape, namely variation of the depth location of the ocular structures, was observed for radiation exposure in the broad radiation geometries.
