Production of a faithful realistic phantom to human head and thermal neutron flux measurement on the brain surface (Cooperative research)

Yamamoto, Kazuyoshi ; Kumada, Hiroaki; Kishi, Toshiaki ; Torii, Yoshiya ; Endo, Kiyoshi*; Yamamoto, Tetsuya*; Matsumura, Akira*; Uchiyama, Junzo; Nose, Tadao*

Thermal neutron flux is determined using the gold wires in current BNCT irradiation, so evaluation of arbitrary points after the irradiation is limited in the quantity of these detectors. In order to make up for the weakness, dose estimation of a patient is simulated by a computational dose calculation supporting system. In another way without computer simulation, a medical irradiation condition can be replicate experimentally using of realistic phantom which was produced from CT images by rapid prototyping technique. This phantom was irradiated at a same JRR-4 neutron beam as clinical irradiation condition of the patient and the thermal neutron distribution on the brain surface was measured in detail. This experimental evaluation technique using a realistic phantom is applicable to in vitro cell irradiation experiments for radiation biological effects as well as in-phantom experiments for dosimetry under the nearly medical irradiation condition of patient.