Therapeutic efficacy for hepatocellular carcinoma by boric acid-mediated boron neutron capture therapy in a rat model.

BACKGROUND Hepatocellular carcinoma (HCC) is a common malignant tumor with poor prognosis. Boron neutron capture therapy (BNCT) may provide an alternative therapy for HCC. This study investigated the therapeutic efficacy of boric acid (BA)-mediated BNCT for HCC in a rat model. MATERIALS AND METHODS The pharmacokinetic and biodistribution of BA in N1S1 tumor-bearing rats were analyzed. Rats were injected with 25 mg B/kg body weight via tail veins before neutron irradiation at the Tsing Hua Open-pool Reactor, and the efficacy of BNCT was evaluated from the tumor size, tumor blood flow, and biochemical analyses. RESULTS HCC-bearing rats administered BNCT showed reductions in tumor size on ultrasound imaging, as well as an obvious reduction in the distribution of tumor blood flow. The lesion located in livers had disappeared on the 80th day after BNCT; a recovery of values to normal levels was also recorded. CONCLUSION BA-mediated BNCT is a promising alternative for liver cancer therapy since the present study demonstrated the feasibility of curing a liver tumor and restoring liver function in rats. Efforts are underway to investigate the histopathological features and the detailed mechanisms of BA-mediated BNCT.