Estimation of photon-isoeffective and RBE-weighted doses in the accelerator-based neutron field

Sato, Tatsuhiko   ; Masunaga, Shinichiro*; Takada, Kenta*; Kumada, Hiroaki*; Hamada, Nobuyuki*

In this study, the depth distributions of the two types of dose, photon-isoeffective dose and RBE-weighted dose, in a phantom placed at an accelerator-based BNCT field were calculated using Particle and Heavy Ion Transport code System, PHITS, coupled with an extended stochastic microdosimetric kinetic model. Compared with the corresponding RBE-weighted dose, the calculated photon-isoeffective dose was larger at lower absorbed dose and was smaller at higher absorbed dose, primarily due to the consideration of the dose dependence of RBE.