Evaluation of the radiation dose for whole body in boron neutron capture therapy

Boron neutron capture therapy (BNCT) is a radiation treatment for cancer that uses charged particles from the ¹⁰B(n, α)⁷ Li reaction. The dose from the resulting alpha particles and ⁷Li nuclei is called the boron dose, and is the primary dose delivered to tumor cells. Dose to the tumor and surrounding cells during neutron beam irradiation comes not only from the boron dose, but also from dose resulting from the reaction between neutrons and the elements in living tissue, as well as from leakage photons from the reactor core. Those doses other than the boron dose contribute dose not only to tumor cells, but also to healthy tissue. BNCT is performed in consideration of the results of a comprehensive and accurate dose distribution evaluation, but this evaluation is performed only within the localization of the tumor. In this study, we defined the full-body phantom in Monte Carlo code 'PHITS'. And we evaluated the dose distribution in full-body phantom resulting from BNCT irradiation. Moreover, we also evaluated the radiation shield material that we proposed for effective techniques to reduce the undesirable radiation exposure dose for non-target area during BNCT. (author)