Neutron activation survey on patients following BNCT clinical trials at THOR

In this work neutron activation surveys on 26 patients of recurrent head and neck cancer following boron neutron capture therapy (BNCT) were performed. By means of qualitative neutron activation analysis (NAA), radioactive nuclides activated from neutron capture reaction within patients were identified. The estimated activities of the corresponding radioactive nuclides were achieved based on several assumptions. Gamma-ray dose rate measurements utilizing a survey meter were taken at three chosen distances, namely, 0 cm, 30 cm and 100 cm away from the irradiated region of patients. The variations of gamma-ray dose rate against time were obtained. An approach to estimating the gamma-ray dose rate resulted from each individual radioactive nuclide is also presented.