Boron neutron capture therapy for advanced salivary gland carcinoma in head and neck

Boron neutron capture therapy (BNCT) is among the radiation treatments known to have a selective lethal effect on tumor cells. This study summarizes the tumor responses and the acute and late adverse effects of BNCT in the treatment of patients with both recurrent and newly diagnosed T4 salivary gland carcinoma. Two patients with recurrent cancer and 3 with newly diagnosed T4 advanced malignancy were registered between October 2003 and September 2007, with the approval of the medical ethics committees of Kawasaki Medical School and Kyoto University. BNCT was performed, in a single fraction using an epithermal beam, at Japan Research Reactor 4. All patients achieved a complete response within 6 months of treatment. The median duration of the complete response was 24.0 months; the median overall survival time was 32.0 months. Three of the 5 patients are still alive; the other 2 died of distant metastatic disease. Open biopsy of the parotid gland after BNCT was performed in 1 patient and revealed no residual viable cancer cells and no serious damage to the normal glandular system. Although mild alopecia, xerostomia, and fatigue occurred in all patients, there were no severe adverse effects of grade 3 or greater. Our preliminary results demonstrate that BNCT is a potential curative therapy for patients with salivary gland carcinoma. The treatment does not cause any serious adverse effects, and may be used regardless of whether the primary tumor has been previously treated.