PURPOSE: Boron neutron capture therapy (BNCT) is among the radiation treatments known to have a selective lethal effect on tumor cells. In this report, we summarize our clinical results for BNCT for the treatment of head and neck cancer at our institution.
METHODS: We started clinical studies for the treatment of head and neck cancer in 2003. Since then, we have completed the following four clinical studies: (1) an analysis of the accumulation of BPA in the tumor and surrounding normal tissue using an 18FBPA-PET study, (2) a BNCT clinical trial for recurrent head and neck cancer, (3) a BNCT clinical trial for head and neck melanoma, and (4) a BNCT clinical trial for newly diagnosed advanced head and neck cancer. All the patients provided consent, and the study was approved by the medical ethics committees of Kawasaki Medical School and Kyoto University. BNCT was performed in a single fraction using an epithermal beam at the Kyoto University Research Reactor and the Japan Research Reactor 4.
RESULTS: The 18FBPA-PET study showed no difference in the T/N ratio between an SCC and a non-SCC group. Overall, 83% of the patients had a T/N ratio of more than 2.5. The response rates were more than 80% for all the BNCT clinical studies. Although mild alopecia, xerostomia, and fatigue were observed in all the patients, no severe adverse effects of grade 3 or higher occurred in these patient series.
CONCLUSIONS: Our preliminary results demonstrated that BNCT is a potentially curative therapy for patients with head and neck cancer. The treatment does not cause any serious adverse effects and can be used regardless of whether the primary tumor has been previously treated.
