Construction of adult Japanese voxel phantoms with various body sizes and their applications to evaluation of organ doses due to external photon irradiation

The authors newly developed the deformation adult Japanese male (DJM) and female (DJF) voxel phantoms with eight different body sizes by modifying the average adult Japanese male (JM-103) and female (JF-103) voxel phantoms. These adult Japanese phantoms were used to calculate organ doses due to external photon exposures. The calculated organ doses were compared with those of the ICRP reference male (RCP-AM) and female (RCP-AF) phantoms with standard Caucasian physiques. The perimeters such as bust, chest, waist and hip of DJM and DJF were adjusted to the length, which were calculated by adding or subtracting n standard deviation (σ) units to or from the averages of adult Japanese. The DJM and DJF with perimeters, which difference with Japanese average was n σ units, were named the DJMn σ and DJFn σ (n =-3 ∼ +5), respectively. The physiques of DJMn σ and DJFn σ were corrected to the average heights or weights of the adult Japanese. In most cases, the organ doses of DJM-2 σ, DJM+2 σ, DJF-2 σ and DJF+2 σ agreed with those of RCP-AM and RCP-AF within 10% for ISO geometry at 0.3 MeV. The body mass indices (BMIs) of DJM-2 σ or DJF-2 σ and DJM+2 σ or DJF+2 σ are approximately equal to 18 and 28, respectively. Approximately 90% of adult Japanese male or female correspond to BMI range of 18 to 28. It can be concluded that the impact of body size variations of adult Japanese on application of organ doses by RCP-AM and RCP-AF to dose assessment for radiation protection is not significant. (author)