Intraperitoneal P-32 is not an effective consolidation therapy after a negative second-look laparotomy for epithelial carcinoma of the ovary

Thirty-four patients with epithelial carcinoma of the ovary were entered into a trial of adjuvant intraperitoneal P-32 following induction chemotherapy and a negative second-look laparotomy. The breakdown by initial Stage was Stage IC, 5; Stage II, 3; Stage III optimal, 22; and Stage III suboptimal, 4. Previous treatment consisted of 4-12 cycles (median 6) of cisplatin or carboplatin-based combination chemotherapy. Fifteen millicuries of P-32 were instilled via a Tenckhoff catheter placed at the time of second-look laparotomy. Because of a 22% incidence of bowel injury in the first 23 patients, the P-32 dose was reduced to 12 mCi in the last 11 patients. To date, there have been no bowel injuries at the lower dose. Eighteen of the 34 (53%) patients have relapsed with a median time to relapse of 20 months and a median follow-up for all patients of 31 months. There has been no difference in the relapse rate between a dose of 12 and 15 mCi. Intraperitoneal P-32 does not appear to reduce the relapse rate following a negative second-look laparotomy. The incidence of bowel injury is dose dependent and is higher than that seen in patients treated as an adjuvant following initial surgery without subsequent chemotherapy or second-look laparotomy.