Efficacy And Safety Of Three Or More Courses Of Radiation For Head And Neck Malignancies

Recurrent head and neck cancers are associated with significant morbidity and mortality. Salvage treatments are poorly defined and the outcomes of more than two courses have not yet been described. In this study, we investigate the safety and feasibility of delivering three or more courses of radiation with overlapping fields in patients with recurrent head and neck malignancies. A single-institution database of 3,063 patients who underwent head and neck radiation between 2011 and 2017 was queried for re-irradiation. Treatments plans were reviewed to identify patients who underwent at least three courses of overlapping radiation. Thirty-six patients were identified with three or more courses of head and neck radiation therapy with overlapping fields. Toxicity was assessed using Common Terminology Criteria for Adverse Events version 4.0. Kaplan-Meier survival analysis was performed to calculate median survival times. Thirty-six patients were identified with three or more courses of overlapping radiation to the head and neck region. Thirty-two patients underwent treatment for multiply recurrent disease and 4 patients were treated for metachronous head and neck primary tumors. Radiation therapy spanned from 1984 to 2017 and included external beam photon radiation, intraoperative brachytherapy, and proton radiation. Primary tumor sites included skin (10), oral cavity (5), nasal cavity/paranasal sinus (6), nasopharynx (4), salivary gland (4), larynx (4), oropharynx (3), and thyroid (2). Median age at the start of the third radiation course was 64 years of age. Median time intervals were 27 months between the 1st and 2nd courses of radiation, and 14 months between the 2nd and 3rd courses of radiation. Median doses for the 1st, 2nd, and 3rd courses of radiation were 64, 57, and 44 Gy, respectively. Spinal cord, brainstem, and optic nerves were the most common organs at risk that exceeded institutional guidelines. 10 patients (28%) experienced long-term toxicities of grade 3 or higher, including PEG placement (4), soft tissue necrosis (2), bleeding (2), osteoradionecrosis (1), and tracheoesophageal fistula (1). Median survival after completing three courses of radiation was 15.6 months (95% confidence interval 9.2-32.4 months). Multiple courses of re-irradiation to the head and neck region are feasible with an acceptable toxicity profile.