Intraoperative irradiation for locally recurrent colorectal cancer in previously irradiated patients

Purpose: Information in the literature regarding salvage treatment for pati ents with locally recurrent colorectal cancer who have previously been trea ted with high or moderate dose external beam irradiation (EBRT) is scarce. A retrospective review was therefore performed in our institution to determ ine disease control, survival, and tolerance in patients treated aggressive ly with surgical resection and intraoperative electron irradiation (IOERT) +/- additional EBRT and chemotherapy. Methods and Materials: From 1981 through 1994, 51 previously irradiated pat ients with recurrent locally advanced colorectal cancer without evidence of distant metastatic disease were treated at Mayo Clinic Rochester with surg ical resection and IOERT +/- additional EBRT. An attempt was made to achiev e a gross total resection before IOERT if it could be safely accomplished. The median IOERT dose was 20 Gy (range, 10-30 Gy). Thirty-seven patients re ceived additional EBRT either pre- or postoperatively with doses ranging fr om 5 to 50.4 Gy (median 25.2 Gy). Twenty patients received 5-fluorouracil /- leucovorin during EBRT. Three patients received additional cycles of 5-f luorouracil +/- leucovorin as maintenance chemotherapy. Results: Thirty males and 21 females with a median age of 55 years (range 3 1-73 years) were treated. Thirty-four patients have died; the median follow up in surviving patients is 21 months. The median, 2-yr, and 5-yr actuaria l overall survivals are 23 months, 48% and 12%, respectively. The 2-yr actu arial central control (within IOERT field) is 72%. Local control at 2 years has been maintained in 60% of patients. There is a trend toward improved l ocal control in patients who received greater than or equal to 30 GS EBRT i n addition to IOERT as compared to those who received no EBRT or <30 Gy wit h 2-yr local control rates of 81% vs. 54%. Distant metastatic disease has d eveloped in 25 patients, and the actuarial rate of distant progression at 2 and 4 years is 56% and 76%, respectively. Peripheral neuropathy was the ma in IOERT-related toxicity; 16 (32%) patients developed neuropathies (7 mild , 5 moderate, 4 severe). Ureteral narrowing or obstruction occurred in seve n patients. All but one patient with neuropathy or ureter fibrosis received IOERT doses <greater than or equal to>20 Gy. Conclusion: Long term local control can be obtained in a substantial propor tion of patients with aggressive combined modality therapy, but long-term s urvival is poor due to the high rate of distant metastasis, Reirradiation w ith EBRT in addition to IOERT appears to improve local control. Strategies to improve survival in these poor-risk patients may include the more routin e use of conventional systemic chemotherapy or the addition of novel system ic therapies. (C) 2001 Elsevier Science Inc.