Moderate dose intraoperative and external beam radiotherapy for locally recurrent rectal carcinoma.

BACKGROUND AND PURPOSE: Late adverse effects (i.e. neuropathy, chronic bowel obstruction) limit the effective dose given in intraoperative radiotherapy (IORT) and external beam radiotherapy (EBRT). Initial results of a multi-modality treatment approach using moderate dose IORT and moderate dose EBRT are presented. PATIENTS AND METHODS: Thirty-one consecutive patients with recurrent rectal carcinomas had IORT and EBRT after complete (R0, n = 14) or incomplete resection (R1, n = 9; R2, n = 8). The mean ORT dose was 13.7 Gy (range 12-20 Gy) supplemented with an EBRT dose of 41.4 Gy. Twenty-two patients had preoperative EBRT and 22 patients had concomitant chemotherapy (5-FU, Leucovorine). RESULTS: After a median follow-up of 28 months, 16 patients had re-recurrent disease and 11 patients had died. Nine patients failed locally (four in-field, four marginal and one anastomotic re-recurrence), three combined with distant metastasis, resulting in overall and IORT infield local control rates of 71% and 87%, respectively. Distant metastases alone were found in seven patients. The 4-year overall and relapse-free survival rates were 58% and 48%, respectively. After incomplete resection the local failure rate increased (R0 21%, R1/2 35%) and the 4-year relapse-free survival rate decreased significantly (29% versus 71%) due to a markedly increased distant metastasis rate (53% versus 7%). Acute and late toxicities were not increased. CONCLUSION: The combination of moderate dose IORT and EBRT is a safe and efficacious component in a multi-modality treatment approach.