Head and neck carcinomas that recur locally after conventional irradiation pose a therapeutic challenge. Boron neutron capture therapy (BNCT) is based on the nuclear capture reaction that occurs when non-radioactive boron is irradiated with neutrons of thermal energy to yield high energy alpha particles and recoiling lithium nuclei. The effect of alpha and 7Li is primarily limited to boron- containing cells. Preferential uptake of boron into cancerous tissue is achieved using boron carriers such as a derivative of phenylalanine, boronophenylalanine (BPA). After administration of BPA by an intra-arterial or intravenous infusion, the tumor site is irradiated with neutrons, the source of which is currently a nuclear reactor. A few uncontrolled clinical trials have evaluated BNCT in the treatment of glioblastoma after brain surgery. In these studies, the median survival times have been 13-15 months after BNCT. However, efficacy and tolerability of BNCT in the treatment of limited number of head and neck cancer patients showed promising results. Though many basic researches about BNCT has been done using Tsing Hua Open-pool Reactor (THOR) at National Tsing Hua University, no clinical trial utilizing BNCT is performed in our country. This study will be the first BNCT trial to treat head and neck cancer in Taiwan.