Feasibility and first results of multimodality treatment, combining EBRT, extensive surgery, and IOERT in locally advanced primary rectal cancer

Purpose: To assess the outcome of aggressive multimodality treatment with p reoperative external beam radiation therapy (EBRT), extended circumferentia l margin excision (ECME) and intraoperative electron beam radiation therapy (IOERT) in patients with locally advanced primary rectal cancer. Methods and Materials: Thirty-eight patients with primary locally advanced rectal cancer, but without distant metastases, received multimodality treat ment. CT-scan showed extension to other structures in 15 patients (39%) and definite infiltration into the surrounding structures in 23 patients (61%) . All patients received preoperative EBRT (dose range 25-61 Gy) and 82% rec eived 50.4 Gy. The resection types were: 12 low anterior resections (31%), 14 abdomino-perineal resections (37%), 6 abdomino-transsacral resections (1 6%), and 6 pelvic exenterations (16%). The IOERT dose ranged from 10 to 17. 5 Gy depending on the completeness of the resection. Results: There was no perioperative mortality. The resection margins were m icroscopically negative in 31 patients (82%), microscopically positive in 4 (10%), and positive with gross residual disease in 3 patients (8%). Pelvic recurrences were observed in 5 patients (13%) including 3 IOERT infield fa ilures. The overall 3-year local control, disease-free survival (DFS), and survival rates were 82%, 65%, and 72%, respectively. Negative resection mar gins were the most significant prognostic factor with regard to DFS (p = 0. 0003) and distant control (p = 0.002) compared with cancer involved surgica l margins. Conclusion: A high percentage of curative resections can be achieved in thi s group of patients with locally advanced rectal cancers. Adding IOERT to p reoperative EBRT and ECME achieves high local control rates and possibly im proves survival. (C) 2000 Elsevier Science Inc.