Distributions of sulfhydryl borane monomer and dimer in rodents and monomer in humans: boron neutron capture therapy of melanoma and glioma in boronated rodents.

Abstract

Boron neutron capture therapy (BNCT), a form of radiation therapy based on the 10B(n,α)7Li nuclear reaction,1,2 has been used in Japan for radiation therapy of human malignant gliomas after total or partial neurosurgical excision of visible tumor.3 Japanese data for 10B distribution in the blood and tumor of 30 patients with malignant glioma have been summarized.4 The stable isotope 10B was introduced into the tumor during a 1–2 hour intra-arterial infusion of a 10B-enriched preparation of the sulfhydryl borane monomer Na2B12H11SH to a total dose in the range 30–80 mg 10B per kg total body weight. The tumor bed was irradiated for 5–7 hours at a 100-kW nuclear reactor, 11 to 16 hours after the infusion. The average tumor 10B concentration just before irradiation was 22 μg 10B/g, while the average blood 10B concentration was 18 μg 10B/g.4 Despite low tumor:blood 10B concentration ratios just before irradiation (average ratio = 1.2:1.0), post-operative survival after BNCT was unexpectedly prolonged for some patients--indeed astonishingly so for a 66-year-old Japanese man who is neurologically and neuroradiologically stable nearly sixteen years after visibly incomplete removal of a malignant glioma.4