RT-06 PLANNING OF BORON NEUTRON CAPTURE THERAPY (BNCT) USING POSITRON EMISSION TOMOGRAPHY (PET)

Boron neutron capture therapy (BNCT) is the particle irradiation therapy that the selective radiation for tumor cells is available for theoretically. The role that the amino acid (phenylalanine) PET (18F-BPA-PET) that we used boronophenylalanine (BPA) which is a boron compound for neutron capture reaction as a tracer carries out is major in our BNCT especially for the recent non-craniotomy BNCT, and it covers by treatment, observation from indication. In this report, we introduce this PET as a principal axis about BNCT and a relation of the PET.In our BNCT, we calculated the drug accumulation to the tumor from BPA-PET before neutron irradiation and reflected it for individual treatment. We become able to decide indication of BNCT by using this PET study, and the indication expansion to other systemic cancers including head and neck cancer and lung, liver is now worked on actively. Also, in other irradiation modalities, they make a radiation plan based on PET study, and several reports to try the improvement of results had been present, however, high radiation doses will be “ exposed “ to the lesion showing high accumulation in BPA-PET in BNCT. We determine the neutron exposure time from the dosage for the normal tissue in the actual treatment, but the Lesion / Normal tissue ratio obtained from BPA-PET is reflected by the evaluation of the tumor dose and the following treatment plan. Also, after the treatment, diagnoses of the pathologic condition such as an increase in tumor volume, a recurrence or the radiation necrosis might be difficult, and we found that the PET study was useful in the follow-up stage for the patients with already treated malignant brain tumor.