Boron-10 quantification and microdosimetric studies in a clinical trial of BNCT

Five boron neutron capture therapy (BNCT) treatments have been delivered as part of the New England Deaconess Hospital-Massachusetts Institute of Technology (MIT) phase-I BNCT dose-escalation protocol for the treatment of metastatic melanoma. The first four irradiations, in which the boron agent boronophenylalanine (L-BPA) was administered orally in a fruit juice suspension, were done using epithermal neutrons from the MIT research reactor employing four fractions. The fifth irradiation, in which the subject received the fructose form of BPA (BPA-f) via intravenous infusion, was delivered in a single fraction. This paper presents the results from the measurements of {sup 10}B concentrations in tumor, normal tissue, and blood for the subjects who underwent this protocol because, to ascribe potential efficacy to BNCT, it is necessary to show that there is an adequate differential uptake of boron by tumor cells relative to normal cells, These measurements used high-resolution quantitative autoradiography, prompt gamma neutron activation analysis, and inductively coupled plasma atomic emissions spectroscopy.