Clinical results of long-surviving brain tumor patients who underwent boron neutron capture therapy.

PURPOSE: The present report is a review of long-term survivors in the patients with malignant brain tumors treated by boron neutron capture therapy. METHODS AND MATERIAL: One-hundred twenty patients with 119 intracranial tumors and one extracranial nerve-related tumor were treated by the current standard technique of boron-neutron capture therapy (BNCT) as of December 1992, using 10B-sodium-mercaptoundecahydrododecaborate.
RESULTS: Out of 87 patients operated on before May 1987, 18 lived or have lived longer than 5 years. Nine of these 18 lived or have lived longer than 10 years out of 53 patients operated on before May 1982. Among more-than-10-year survivors, only two died at 17 and 12 years. All of the other are still alive. The two died of delayed radiation damage because BNCT was applied to glioblastomas which recurred after their conventional radiotherapy. They lacked evidence of tumors when they died. Out of these nine more-than-10-year survivors, three had been previously treated by conventional external radiotherapy and they developed radiation damage which brought all patients ultimately to an incapacitated condition. Two of the three died. All the other 6 who were free from previous radiation history are active in their jobs and have no evidence of tumors.
CONCLUSION: It can be suggested that BNCT is a radiotherapy that can produce "cure" of both malignant and benign brain tumors while preserving a good quality of life if conducted without conventional radiotherapy.