High dose rate intraoperative radiation therapy for recurrent head and neck cancer: The importance of in-field control on survival.

5593 Background: High dose-rate intraoperative radiation therapy (HDR-IORT) offers an opportunity to salvage recurrent patients (pts) and dose-escalate therapy. Methods: From 1/01-2/10, 90 pts with primary (n = 13) or recurrent (n = 77) head and neck cancer total of 101 sites were treated with HDR-IORT. A single fraction (median, 12 Gy; range, 10–17.5 Gy) at a depth of 1cm from the source was delivered after gross total surgical resection (GTR) to close or positive margins. 11 of 90 pts received HDR-IORT to 2 separate sites. Sites treated were; neck 54%, face 13%, parapharyngeal space 11%, parotid 7%, nasal cavity/paranasal sinus 7%, skull base 4% and other 4%. Histology was squamous cell carcinoma 82%, salivary gland 12%, sarcoma 4%, skin 1%, and esthesioneuroblastoma 1%. GTR was obtained in all pts with positive margins in 51%. Flap reconstruction was performed in 65%. Additional chemoradiotherapy was given to median dose of 45Gy (31-69Gy). Results: No intraoperative complications related to HDR-IORT. L...