Metabolism of borono-phenylalanine–fructose complex (BPA–fr) and borocaptate sodium (BSH) in cancer patients—Results from EORTC trial 11001

Within the clinical trial EORTC 11001, patients were infused with 10B-enriched borono-phenylalanine–fructose complex (BPA–fr), or borocaptate sodium (BSH) solutions, which are used as boron carriers for boron neutron capture therapy. Urine samples were periodically collected and analyzed by 10B NMR spectroscopy. The results revealed time-dependent metabolic changes of the administered compounds. BPA–fr dissociated to the constituents BPA and fructose, and the borate group was partly cleaved from BPA. BSH was partly aggregated to a dimer form, BSSB. These observations were previously reported for cultured cells and animal models, and are confirmed here in human cancer patients.