High Dose-Rate Brachytherapy in Recurrent High-Risk Head and Neck Cancer

Background: Thirty to fifty percent of HNSCC patients treated with chemoradiation therapy present with recurrence and can be treated with maximum debulking surgery combined with re-irradiation. Re-irradiation can be done using external beam radiation therapy (EBRT) or brachytherapy. The advantage of brachytherapy over EBRT is that owing to rapid dose falls off, a higher dose can be delivered to the target area sparing normal tissue. Hence, we evaluated toxicity and outcomes [overall survival (OS) and diseasefree survival (DFS)] in high-risk (HR) recurrent HNSCC patients undergoing re-irradiation using interstitial brachytherapy following surgery. Objectives: To evaluate toxicity and outcomes of re-irradiation using Interstitial High Dose-Rate Brachytherapy (HDR-BRT) in highrisk Head and Neck Squamous Cell Carcinoma (HNSCC) patients. Methods: Ten biopsy-proven recurrentHNSCCpatients treated with primary chemoradiation therapywhohad theHRof the second recurrence at nodal disease were evaluated. All patients underwent surgery followed by the intraoperative placement of catheters in a single plane, at 10 - 12 mm apart and fixed with stay sutures. The CT simulation was done on the 5th - 7th postoperative day. Volumetric optimization was done with a 5-mm dwell position. The dose of 30 Gy/10 Fractions, 3 Gy/Fraction, two fractions per day, 6 hours apart after 5 days was planned. Results: The DFS and OS for the entire cohort in 1 and 2 years were 60% and 40%, respectively. One patient had carotid blowout where the disease was stuck to the carotid vessel. No other significant acute or late toxicity was noted. Conclusions: The HDR-interstitial brachytherapy in the recurrent HR, HNSCC with the intraoperative placement of catheters at tumor bed provides reasonably good local control without significant acute or late toxicity.