Boron neutron capture therapy for glioblastoma multiforme

Glioblastoma multiforme (GBM) is an incurable disease that can only be managed in a palliative way. The GBM accounts for approximately half of all newly diagnosed primary brain tumors with an incidence of 2-3 cases per 100,000 people each year. Surgery and radiation are the standard options for palliation, and whether there is a place for chemotherapy is still discussed. Boron neutron capture therapy (BNCT) is a promising and possibly curative method of treating GBM. The purpose of this article is to provide an updated review on the current management and future possibilities of treating GBM with BNCT.

Use was made of computerized searches and of checking cross-references of articles and book chapters.

The principle of BNCT uses the high ability of 10B to capture thermal neutrons and to disintegrate immediately into a He nucleus (alpha-particle) and a Li nucleus. To reach a sufficient concentration of 10B in the malignant cells compared to the surrounding healthy tissue, 10B-carriers must be highly tumor-selective. At present, the 10B carriers boronophenylalanine (BPA) and sodium borocaptate (BSH) are used in clinical trials to perform BNCT.

The BNCT is a promising and possibly curative method of treating GBM, but at present this procedure is far from perfect. Because of the lack of selectivity of the boron carriers, it appears so far that radiation toxicity limits the radiation dose, so that tumor damage is modest. Current investigations and developments are aimed at targeting the boron carriers to the tumor, in order to limit the damage to the healthy, surrounding tissue.