176 I. J. Radiation Oncology 0 Biology l Physics Volume 36, Number 1, Supplement, 1996

35 SALVAGE WHOLE ABDOMINAL RADIATION THERAPY FOR OVARIAN CANCER: A TWELVE YEAR EXPERIENCE

Baker, Katherine, M.D.I, Reddy, Susheel, B.S.1, Lee, Myung-Sook M.D. 1, DeGeest, Koen, M.D.2, Lincoln, Sarah, M.D.3, Sarin, Pramilla, M.D.4, Graham, James, M.D.5, Yordan, Edgardo, M.D.6, and Reddy, Salitha, M.D.1

Departments of IRadiation Oncology, *Gynecologic Oncology, and 3Medical Oncology Rush-Presbyterian-St. Luke’s Medical Center, Chicago, IL; lChrist Hospital, Oak Lawn, IL; 5 Hurley Medical Center, Flint, MI, and 6Lutheran General Hospital, Park Ridge, IL.

Purpose: 1)To evaluate whole abdominal radiation therapy (WART) as a salvage modality in patients with epithelial ovarian carcinoma who have failed one or more chemotherapeutic regimens; 2)To assess the feasibility and long-term toxicity of such treatment. Materials and Methods: Between June 1983 and October 1994,51 patients who had failed one or more chemotherapeutic regimens received WART. Forty-seven patients had epithelial ovarian carcinoma, the remaining had primary carcinoma of the peritoneal cavity. Forty patients (78%) had FIG0 stage III and IV disease. Grade III and IV tumors were seen in 29 patients (57%). The residual disease was classified as being either microscopic or macroscopic disease depending on the status after the laparotomy prior to radiation treatment, irrespective of the extent of disease prior to debulking. In 22 patients (43%) macroscopic disease was present after laparotomy, while the remaining 29 patients (57%) had only microscopic disease present. Twenty patients (39%) had residual disease limited to the pelvis, and 31 patients (61%) had upper abdominal involvement. An open field technique was used to deliver planned doses of 25Gy to the whole abdomen with shielding of the kidneys posteriorly after 12Gy. Boost fields to the Pelvis and/or areas of gross residual disease were treated when indicated. The Kaplan-Meier Method was used to calculate survival data from the initiation of radiation until death or recurrence. Median follow-up for surviving patients was 53 months, with a range of 17 to 122 months. Results: Five patients (10%) were unable to complete therapy secondary to acute toxicity. An additional fourteen patients (27%) required a one to five week break usually secondary to cytopenias. Four year actuarial survival and recurrence-free survival rates for the entire group of patients were 32% and 23% respectively. For patients with microscopic residual disease, survival and recurrence-free survival rates were 48% and 37% respectively. This is better than the actuarial survival of 11% and the recurrence-free survival of 5% in patients with macroscopic residual disease. Those patients with disease limited to the pelvis after laparotomy had a 4 year actuarial survival and recurrence-free survival of 60% and 54% respectively. Conversely, when upper abdominal involvement was present survival and recurrence-free survival were 16% and 4% respectively. Log rank tests were done to compare overall survival (OS) and recurrence-free survival (RPS) in specific groups of patients. Statistically significant differences were seen with respect to microscopic versus macroscopic disease remaining after laparotomy (OS p = .OOOl, RFS p = .OoOl), and pelvic disease only versus abdominal disease (OS p = .0019, RFS p = .0002). Ten patients (20%) experienced bowel complications of whom six patients (12%) required surgical intervention. Two patients developed leukemia and one patient developed myelodysplastic syndrome. Conclusion: Whole abdominal radiation therapy is an effective salvage treatment in patients with ovarian carcinoma who have microscopic residual disease or disease limited to the pelvis. The treatment is well tolerated with acceptable long-term toxicity.

36 LONG TERM SURVIVAL WITH WHOLE ABDOMINOPELVIC IRRADIATION (WAI) IN PLATINUM-REFRACTORY OVARIAN CANCER

Anthony J. Cmelak, M.D., Richard S. Cox, Ph.D., Daniel S. Kapp, Ph.D., M.D.

Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305

m: To evaluate the efficacy and toxicity of WAI in persistent or recurrent epithelial ovarian carcinoma after initial chemotherapy.

-and Between 1970 and 1995, 41 women with persistent or recurrent ovarian carcinoma after initial surgical debulking and chemotherapy were treated with WAI. Median age was 57 years (range 27-75). Initial FIG0 stages were I and II - 5 patients (12%) Ill - 26 (64%) and IV - 10 (24%). Tumor grade was I - 4 (10%) II - 16 (39%). and Ill - 20 (49%). Four to eighteen (median eight) cycles of chemotherapy had been given prior to WAI. Thirty-one patients had received platinum-based regimens, and 22 of these had failed within six months after completion of chemotherapy (platinum-refractory). Prior to WAI, 11(27%) patients had microscopic residual disease, 21(51%) had gross residual disease up to 1.5 cm, and 9 (22%) had tumors greater than 1.5 cm in maximal diameter. Median doses of 28 Gy to the abdomen and 46 Gy to the pelvis were delivered using an open-field technique with appropriate liver and kidney shielding.

&9gj&: With follow-up of 1 month to 16.5 years, the [j-year actuarial disease specific survival was 47% in all 41 patients, and 49% in 22 platinum-refractory patients. Both disease bulk at WAI (~~10-4) and initial stage (p=O.O05) were of prognostic value. Five-year disease specific survivals were stage I and II - 100%. stage Ill - 55%. and stage IV - 27%. Five-year disease specific survival of all nonbulky (less than 1.5 cm) patients was 40%; 0% for patients with disease greater than 1.5 cm. Five-year disease specific survival for grade I - 66%, II - 59%, and Ill - 33%. Stage I, II, or Ill patients with residual disease bulk of 1.5 cm or less before WAI had a lo- year actuarial disease specific survival of 50%. Twelve patients (29%) failed to complete the planned course of WAI due to acute toxicity (most often due to prolonged thrombocytopenia). Late bowel toxicity included obstruction in one patient and fistula in one patient.

m: Whole abdominopelvic irradiation should be considered in selected patients who fall mtttal chemotherapy, especially patients with nonbulky platinum-refractory disease. With acceptable toxicity, WAI results appear to be significantly better than second-line chemotherapy.