Intraoperative electron beam radiotherapy (IOERT) in the management of recurrent ovarian malignancies

To investigate disease control, survival outcomes, and tolerance of intraoperative electron beam radiation therapy (IOERT) as a component of treatment for women with recurrent ovarian malignancies.

From November 1987 to January 2009, 20 patients with recurrent ovarian malignancies received IOERT after maximal surgical cytoreduction. Areas treated included the pelvis (14), para-aortic nodes (6), or inguinal nodes (1). The median IOERT dose was 12.5 Gy (range, 10-22.5 Gy). Sixteen patients also received perioperative external beam radiotherapy as a component of treatment (median, 50 Gy; range, 20-54.3 Gy). All patients were followed prospectively for outcome and toxicity evaluation.

Median follow-up for surviving patients was 76.2 months (range, 1.5-175.8 months). The 5-year Kaplan-Meier estimate of local control was 59%, and central control (within the IOERT field) was 76%. All local relapses occurred in patients who had microscopic margin-positive resections. The 5-year freedom from distant relapse was 37%. The median disease-free interval after IOERT was 14 months. The median survival was 30 months, and the 5-year Kaplan-Meier estimate of survival was 49%. Six patients (29%) experienced grade 3 or higher toxicities, 2 of which (10%) were at least partly attributable to IOERT. Three patients experienced grade 1 or 2 peripheral neuropathy related to IOERT.

Combined modality therapy with external beam radiotherapy, surgery, and IOERT is an option for the treatment of localized recurrent ovarian cancer, with acceptable rates of in-field failure and toxicity. Durable disease control is possible in select women treated with this regimen.