PHANTOM EXPERIMENT AND CALCULATION FOR INVIVO B-10 ANALYSIS BY PROMPT GAMMA-RAY SPECTROSCOPY

In order to determine B-10 concentrations in a tumour in vivo without injuring tissues, phantom experiments and calculations were carried out for boron neutron capture therapy. The experiment was based on prompt gamma ray spectroscopy and a single-crystal silicon-filtered neutron beam from a TRIGA-II reactor. Calibration curves to determine the B-10 concentrations in the tumours were experimentally generated from known B-10 values for simulated tumours with various volumes in a phantom. The B-10 distributions in a tumour were also investigated and it was possible to distinguish the tumour with B-10 from normal tissue without B-10. In addition, the B-10 concentrations were estimated by calculations. A two-dimensional discrete ordinate transport code, DOT3.5, was employed for the calculations of the neutron fluence rate distributions in a phantom. The number of incidental gamma rays entering a germanium detector, which were produced in a tumour as a result of neutron reaction, were calculated by an analytical method. The results were in good agreement with the experiments.