Absorbed fractions for multi-region models of the kidneys in ICRP/ICRU voxel phantoms

ICRP/ICRUボクセルファントムの腎臓マルチリージョンモデルの吸収割合

木名瀬 栄   ; 木村 仁宣 ; 高原 省五  ; 本間 俊充

Kinase, Sakae; Kimura, Masanori; Takahara, Shogo; Homma, Toshimitsu

In the present study, the ICRP/ICRU kidney models were applied to evaluating AFs for the kidneys. Uniformly distributed photon sources with the energy range from 10 keV to 10 MeV were assumed to be in the cortex, medulla and pelvis. The radiation transport was simulated using the Monte Carlo code EGS4 in conjunction with an EGS4 user code, UCSAF. Consequently, it was found that the AFs with the ICRP/ICRU kidney models were consistent with those with the MIRD kidney model for adult. In the case of cross-irradiation AFs, the largest differences between the two kidney models (ICRP/ICRU and MIRD) were found to be 3.3 for the female and 2.6 for the male in the low-energy region. The AFs obtained in the present study would be useful for non-uniformly distributed source of photons in kidney dosimetry.