Hyperfractionated split-course whole abdominal radiotherapy for ovarian carcinoma: tolerance and toxicity.

Whole abdominal irradiation after chemotherapy and second look laparotomy for advanced ovarian carcinoma is poorly tolerated because of hematologic toxicity that frequently necessitates interruption or abandonment of treatment. A new treatment strategy using a hyperfractionated split course schedule to deliver a total of 30 Gy in 30 fractions over 6 weeks was designed in an attempt to overcome this problem, while not compromising the tolerance of late reacting normal tissues. Of 23 patients treated between August 1984 and June 1986, only one failed to complete therapy as scheduled. Six patients with gross residual disease also received a limited field boost of 15 Gy in 15 fractions after completion of treatment to the whole abdomen. None of these six patients achieved disease control, and five required surgery for intestinal obstruction with pathologic evidence of radiation bowel injury. Of the 17 patients who received no boost, five developed gut obstructions associated with tumor recurrence and not attributable to irradiation. We conclude that whole abdominal irradiation using the hyperfractionated split course schedule without a boost is safe and feasible but its therapeutic efficacy appears confined to subsets of patients with no visible residual disease at the time of second look laparotomy, or in whom all visible residual tumor can be resected.