Boron neutron capture therapy as a larynx-preserving treatment for locally recurrent laryngeal carcinoma after conventional radiation therapy: a preliminary report

Abstract Background : Preserving voice function is difficult in patients with local recurrence of laryngeal carcinoma after radiotherapy. The purpose of this study was to evaluate the efficacy and safety of boron neutron capture therapy (BNCT) for residual or recurrent laryngeal carcinoma after radical laryngeal cancer irradiation. Methods and materials : This study included 10 patients who underwent BNCT for residual or recurrent laryngeal carcinoma after radical laryngeal cancer irradiation. Before BNCT, the recurrent laryngeal carcinoma stage was rT2N0, rT2N1, rT3N0, rT3N1, and rT4aN0 in four, one, two, one, and two patients, respectively. All patients underwent a prophylactic tracheostomy before BNCT. Results : The response rate at 3 months after BNCT in 10 patients with locally recurrent laryngeal cancer was 90%, including 8 patients with complete response, one patient with partial response, and one patient with stable disease. Five of 10 patients were recurrence-free with a median follow-up of 12 months (8-23 months) after BNCT. The site of recurrence was local in three patients and cervical lymph nodes in the other two patients. All recurrent cases were salvageable except for one case of recurrence in a lateral cervical lymph node. The most frequent adverse event associated with BNCT was laryngeal edema, which almost resolved after one week in all patients. No other grade 4 or higher adverse events occurred. Conclusions : BNCT can be used to administer radical doses to tumor tissues after radical irradiation. Early detection of recurrence and BNCT are expected to improve the cure rate for recurrent laryngeal carcinoma.