[2M04-08] Dose Evaluation

[2M08] Evaluation of internal exposure effect in consideration of internal activation during boron neutron capture therapy

*Ryosuke Narita¹, Tatsuhiko Sato², Hiroki Tanaka¹, Takushi Takata¹, Yoshinori Sakurai¹ (1. Kyoto Univ., 2. JAEA)

Keywords:BNCT, Monte Carlo simulation, dose evaluation, activation, computational phantom

From the viewpoint of radiation protection and quality assurance for boron neutron capture therapy (BNCT) systems, it is important to estimate the exposure dose of the patient's normal tissue. Particularly, thermal and epithermal neutrons are incident to the patient, so that components constituting the body are possibly activated. Previous studies have suggested that the ²⁴Na and ³⁸Cl produced by the neutron activation have a significant effect on radiation exposure. In order to evaluate the exposure dose more accurately, the effect of internal exposure for the neutron activation in the body was evaluated. The effect of the internal exposure due to the activation in BNCT on normal tissues was evaluated to be five orders smaller than the external exposure. Therefore, it is not essential to consider about the internal exposure for the daily treatment planning and QA/QC.