Impact of tumor volume-directed involved field radiation therapy integrated in the management of recurrent ovarian cancer

Objectives. Assess the role of involved field radiation therapy (IFRT) in recurrent ovarian cancer. Methods. Thirty-five patients with a diagnosis of epithelial ovarian cancer received radiation therapy at LUMC between 1991 and 2001. Of these, 20 received tumor volume-directed IFRT for localized extraperitoneal recurrences (either as consolidation following debulking surgery or as attempted salvage if unresectable) and form the basis of this report. All patients were heavily pretreated with multiple chemotherapy regimens. Eleven patients had optimal debulking of their recurrences prior to radiation. IFRT was primarily with external beam (median dose 50.4 Gy). Appropriate statistical analyses evaluated association among disease-free (DFS), overall survival (OS), local recurrence-free (LRFS), and various prognostic factors. LRFS was defined as freedom from in-field recurrences and was considered as a measure of effectiveness of radiotherapy. Results. Of 20 patients, 17 had a complete response after RT. The actuarial LRFS, OS, and DFS at 5 years from date of radiation were 66%, 34%, and 34%, respectively. The LRFS at 3 years was 89% for those with optimal resection vs. 42% for those with gross residual/unresectable tumor, which was significantly better (P = 0.04). The corresponding 3-year DFS was 72% vs. 22% and 5-year OS was 50% vs. 19%, respectively. Acute complication of RT was mild, half had Grade 1-2 gastrointestinal (GI) toxicity, three patients had Grade 3-4 late GI effects. Conclusion. IFRT is effective in controlling localized recurrences of ovarian cancer, especially after they are optimally debulked (89% local control and 50% 5-year overall survival in this subgroup), and is relatively well tolerated in these heavily pretreated patients.