Objective: The aim of this study was to review the experience with intraoperative radiation therapy (IORT) in the treatment of gynecologic cancers at the Massachusetts General Hospital.

Methods: From January 1, 1994 to December 31, 2011, 32 patients were treated with IORT at Massachusetts General Hospital. Hospital, pathology, and office medical records and radiation oncology records were reviewed. The Kaplan-Meier method was used to generate disease-free survival and overall survival (OS) data.

Results: In 27 patients (84.4), surgical resection margins were microscopically positive. In 5 patients (15.6%), margins were grossly positive. For patients with microscopic disease, 5-year disease-free survival was 40.9% (57 mo), compared with 9.1% (23 mo) for those with gross residual disease (P=0.001). Five-year OS was also statistically improved for patients with microscopic residual disease, when compared with OS among patients with gross residual disease, 77.3% (93 mo) and 54.5% (40 mo), respectively (P=0.001). The risk of distant metastases in patients with gross residual disease was 87%, compared with 28% in patients with microscopic disease (P=0.02).

Conclusions: Volume of residual disease before IORT is an important prognostic indicator. Local recurrence and distant metastases were more common among patients with gross residual disease left in situ at time of IORT. Our institutional experience with IORT further supports the importance of complete surgical resection.