Definitive re-irradiation using intensity-modulated radiation therapy in cancers of the head and neck, focusing on rare tumors.

Purpose: To analyze the outcomes following re-irradiation for local recurrence of rare head and neck tumors.
Material and Methods: We retrospectively analyzed 11 patients who had received intensity-modulated radiation therapy (IMRT) for recurrent tumors in the head and neck except for laryngopharynx.
Results: Primary tumor sites included the maxillary sinus, nasal cavity, and external ear canal in six, three, and two patients, respectively. The median follow-up times were 13 (range, 3-54) months. The median survival time was 17 months with 1- and 2-year survival rates of 63.64 and 39.77%, respectively. Among 11 patients, five experienced local failure in the follow-up period. The 1- and 2-year local control rates were 58 and 47%, respectively. Patients who had received a radiation dose of ≥3 Gy per fraction showed significantly better local control than those receiving less (p = .0419). One patient experienced Grade 3 facial pain as acute toxicity. Late toxicities included radiographic findings of partial central nervous system necrosis in three patients and Grade 3 osteonecrosis and Grade 3 facial nerve disorder in one patient.
Conclusions: Re-irradiation of rare head and neck tumors using IMRT for loco-regional recurrence may be an acceptable treatment option.