Evaluation of whole abdominal irradiation in ovarian carcinoma with a four orthogonal fields technique.

Purpose: The purpose of this study is to evaluate the toxicity and the results of abdominopelvic irradiation with a four orthogonal field's technique in patients with ovarian carcinoma.
Methods and Materials: Between May 1981 and December 1990, 167 patients with ovarian carcinoma have been treated with whole abdominal irradiation: 62 patients with no or minimal residual disease < 2 cm after initial surgery (group 1) and 105 patients with no residual disease or macroscopic residual disease < 2 cm assessed by second-look surgery after incomplete debulking surgery and cisplatin-based polychemotherapy (group 2). Irradiation was performed by a four orthogonal field's technique. Thirty grays were given with a 25 MV photon beam (1.5 Gy/fraction/day, 20 fractions over 30 days). Boosts were performed in 50 cases (median dose of 15 Gy).
Results: With a median follow-up of 68 months, the 5-year actuarial survival rate was 50% in the entire group, 67% in group 1, 40% in group 2, and 84% in T1, 61.5% in T2, 38% in T3. Five-year actuarial survival was analyzed according to the residuum: (a) after initial surgery (no residual disease: 70%, residual disease: 36.5%), (b) after second-look surgery: 76% in patients with a negative second look, 66% in patients with microscopic residual disease, 22% in patients with macroscopic residual disease and secondary surgical reduction, and 10% in patients with small unresectable nodules. Nine percent of the patients failed to complete irradiation acute side effects related. Five percent required surgery for bowel obstruction.
Conclusion: The abdominopelvic irradiation with this four orthogonal field's technique was associated with tolerable acute toxicity and a low risk of serious late complications. Similar late results to have been reported whole abdominal irradiation with chemotherapy in patients with negative or microscopic residual disease after surgery. Randomized trials comparing these two adjuvant treatments are warranted.