 BPA is infused as a fructose complex BPA-F into a peripheral vein over 2 hours prior to neutron irradiation. Blood samples will be taken before starting the BPA infusion, and thereafter at 20 to 40 minute intervals during the infusion, following infusion, and after delivering neutron irradiation to monitor the blood boron concentration. The blood samples will be analyzed for boron to estimate the average blood boron level during neutron irradiation. A minimum tumor dose of 17 Gy W is given while limiting the normal brain maximum peak dose to 8 Gy W, and the average normal brain dose to 6 Gy W. The first 10 patients will be given BPA 290 mgkg, following which the BPA dose will be escalated in cohorts of 3 subjects gradually up to 450 mgkg, provided that protocol-specified unacceptable toxicity will not occur. 