Intraoperative radiation therapy in gynecologic cancer: update of the experience at a single institution.

PURPOSE: To update the Mayo Clinic experience with intraoperative radiation therapy (IORT) in patients with gynecologic cancer. METHODS AND MATERIALS: Between January 1983 and June 1991, 39 patients with recurrent or locally advanced gynecologic malignancies received intraoperative radiation therapy with electrons. The anatomical area treated was pelvis (side walls or presacrum) or periaortic nodes or a combination of both. In addition to intraoperative radiation therapy, 28 patients received external beam irradiation (median dose, 45 Gy; range, 0.9 to 65.7 Gy), and 13 received chemotherapy preoperatively. At the time of intraoperative radiation therapy and after maximum debulking operation, 23 patients had microscopic residual disease and 16 had gross residual disease up to 5 cm in thickness. Median follow-up for surviving patients was 43.4 months (range, 27.1 to 125.4 months).
RESULTS: The 5-year actuarial local control with or without central control was 67.4%, and the control within the IORT field (central control) was 81%. The risk of distant metastases at 5 years was 52% (82% in patients with gross residual disease and 33% in patients with only microscopic disease postoperatively). Actuarial 5-year overall survival and disease-free survival was 31.5 and 40.5%, respectively. Patients with microscopic disease had 5-year disease-free and overall survival of 55 and 50%, respectively. Grade 3 toxicity was directly associated with IORT in six patients (15%).
CONCLUSION: Patients with local, regionally recurrent gynecologic cancer may benefit from maximal surgical debulking and IORT with or without external beam irradiation, especially those with microscopic residual disease.