Intraoperative electron beam radiotherapy for locoregionally persistent or recurrent head and neck cancer

To report our institutional experience with intraoperative radiotherapy for persistent or recurrent head and neck cancer.

Sixty-one patients were treated with salvage surgery and intraoperative radiation therapy (IORT). Fifty-eight patients (95%) had previously received external beam radiotherapy (EBRT) as a component of their definitive therapy. Forty-four patients (72%) had squamous cell carcinoma (SCC). Surgical margins were positive in 28 patients (46%). IORT was prescribed to a median dose of 12.5 Gy (range, 10-17.5). Twenty-three patients (38%) received a course of postoperative EBRT (median 45 Gy). Clinical outcomes were retrospectively reviewed and univariate analysis was performed using log-rank tests to correlate clinical outcomes with histology, surgical margin, and adjuvant therapy.

Median follow-up among surviving patients was 15.9 months. Median progression-free survival (PFS) and overall survival (OS) were 9.8 and 19.1 months, respectively. One- and 2-year rates of locoregional control (LRC) were 59% and 35%, respectively. One- and 2-year rates of PFS were 39% and 19%, respectively. One- and 2-year rates of OS were 62% and 42%, respectively. Overall survival was better for non-SCC histology (P = .03). For SCC patients, negative surgical margin showed a trend toward improved PFS (P = .09) and OS (P = .06). There was one grade-5 toxicity due to carotid rupture.

IORT has shown effective LRC and OS with an acceptably low rate of severe toxicity at our institution. OS was significantly better for non-SCC histology. For SCC patients, there is a trend toward improved PFS and OS associated with negative surgical margins.