10162- TB-6 VALIDATION OF BORON NEUTRON CAPTURE THERAPY WITH EXISTING BORON COMPOUNDS IN A RAT MALIGNANT GLIOMA MODEL

Abstract BACKGROUND Boron neutron capture therapy (BNCT) is a biologically targeted particle therapy that utilizes the capture reaction between boron and neutrons. Theoretically, tumor cell-selective boron uptake allows for tumor-selective therapy. Recently, BNCT using an accelerator neutron source has been initiated in the area of head and neck cancers and is expected to expand its application to brain tumors. In addition to boronophenylalanine (BPA), which is used in clinical practice, clinical trials for malignant gliomas have been conducted in the past using sodium borocaptate (BSH) in combination. However, to date, surprisingly few reports have accurately evaluated the validation of BNCT with BPA and BNCT with BPA/BSH in animal models. In the present study, we performed a basic research-based validation of BPA/BSH combined BNCT that has been performed in clinical trials in the past. METHODS Brain tumor models of F98 rat malignant glioma brain tumors were prepared. BPA and BSH were administered intravenously 2.5 hours and 12 hours before BNCT were performed, respectively. Each F98 rat malignant glioma brain tumor model was neutron irradiated and evaluated using Kaplan-Meier survival curves. RESULTS No significant difference in survival was observed in the BSH alone group compared to the untreated group. A significant difference in survival was observed in the BPA alone group compared to the untreated group. The BPA/BSH combination group had the longest median survival and a significant difference in survival compared to the untreated group. A significant difference in survival was observed between the BPA/BSH combination group and the BSH alone group. CONCLUSION The combination of BPA and BSH improved BNCT efficacy and prolonged survival. The combination of BPA and BSH, existing boron compounds, is a pioneering method of boron neutron capture therapy using two and more boron compounds, and its use is presumed to have been highly rational.