Adjuvant whole abdominal radiotherapy in epithelial cancer of the ovary.

PURPOSE: To reexamine the use of adjuvant radiotherapy in optimally debulked patients. METHODS AND MATERIALS: Between January 1985 and April 1998, 60 patients were treated with adjuvant whole abdominal radiotherapy (A-WART). The stage distribution was Stage IC in 17 patients, Stage II in 9, and Stage III in 34. The grade distribution was Grade 1 in 9 patients, Grade 2 in 27, and Grade 3 in 24; thus, 60% of the patients had Stage III disease and 40% had Grade 3 tumors. After surgery, no residuum was left in 42 (70%), <or=2 cm in 13 (22%), and >2 cm in 5 (8%) of 60 patients. Of the 60 patients, 19 also received platinum-based chemotherapy; in 12 of the 19, the chemotherapy was before A-WART. Thirty-seven of the patients had undergone previous abdominal procedures and a second-look operation was performed in 25% of them. A-WART consisted of 22 Gy in 22 fractions, at 5 fractions weekly in 90% of the patients. The remaining 10% received 25 Gy in 25 fractions within 5 weeks. The A-WART was delivered using a 4-MV linear accelerator. After abdominal irradiation, a boost to the pelvis was given to reach 45 Gy at 1.8 cGy/fraction, using a 4-15-MV linear accelerator.
RESULTS: Treatment was delivered in a median of 50 days (range 48-70). In 12 (20%) of the 60 patients, a transient treatment interruption occurred because of acute toxicity, mainly vomiting and diarrhea. The overall survival rate was 55% at 5 years (median follow-up 96.5 months). Patients with low-histologic grade tumors (Grade 1-2) had a better 5-year survival rate (66%) than those with Grade 3 tumors (35%; p <0.03). A tendency for better survival was found for those with Stage I-II than for those with Stage III (69% vs. 43%). Nonetheless, this difference did not reach statistical significance (p = 0.17). For patients receiving chemotherapy, the 5-year survival rate was 51%, not statistically different from the 58% 5-year survival rate observed among those patients without adjuvant chemotherapy (p = 0.9). The abdominal control rate was 83%. Thirty-five percent of the patients sustained acute Grade 2-3 complications. Late complications were observed in 6 of 60 patients, 4 had Grade 3 (7%) and 2 had Grade 4 (3%). Two patients died of intestinal occlusion, both had undergone previous abdominal procedures and in 1, no tumor was found in the abdomen at the postmortem examination.
CONCLUSION: A-WART achieves a quite favorable 5-year survival rate with a low complication rate in properly selected patients. A-WART should be included in the elective postoperative treatment of ovarian cancer patients who are at risk of abdominal failure, and this should be explored in a randomized trial.