Head and neck(H & N) 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 intravenous infusion, the tumor site is irradiated with neutrons, the source of which is currently a nuclear reactor, like the Tsing Hua Open-Pool Reactor (THOR), a 2MW research reactor at National Tsing Hua University (NTHU) in Taiwan. Since it is a target radiotherapy, low complication rate after BNCT can be obtained. However, further local recurrence after BNCT for recurrent H & N cancer was reported in several publications.