Neutron Activation Dose Assessment Based on a Human Head Phantom Post-BNCT

This study aims to assess the residual radioactivity produced in the human head phantom following irradiation from a boron neutron capture therapy neutron source based on a 2.8 MeV proton accelerator. Using Monte Carlo software to simulate irradiation on a head phantom based on ICRP Publication 110, it was found that, in addition to the nuclides 24 Na, 38 Cl, and 42 K reported in other literature, 32 P is the nuclide that contributes the most to the internal exposure dose in patients post-BNCT. Calculations indicate that the effective dose resulting from 60 min of irradiation activation ranges between 148 and 401 μSv, which is relatively low. This study also analyzed the dose rate at a distance of 60 cm from the activated head. Approximately 5 min after irradiation ends, short-lived nuclides such as 19 O and 20 F decay completely, reducing the dose rate to below 1 μSv h -1 . Although nuclides like 24 Na will continue to emit radiation, the dose rate remains at a safe level.