Treatment of locally advanced rectal cancer with external beam radiation, surgical resection, and intraoperative radiation therapy.

To try to improve the local control and survival of patients with locally advanced rectal cancer we have used a combination of high-dose pre-operative radiation therapy to 5,040 cGy followed by surgical resection and intraoperative electron beam radiation therapy (IORT) when there was visible or palpable residual disease, microscopically positive surgical margins, or persisting tumor adherence. A total of 75 patients were taken to surgery for resection +/- IORT who did not have distant metastases. Of the 49 patients with primary tumors, 11 did not have IORT as the tumor was thought to be completely resected. Of these 11, there were two local recurrences and a 3-year survival of 71%. Thirty-six patients with primary tumors had resection (20 complete, 16 partial) plus IORT, with a 3-year survival of 58% and three local failures. Twenty-six additional patients were treated for locally advanced recurrence of whom four could not receive IORT because of pelvic size or the extent of tumor. Of the 22 who received IORT, 7/9 with complete resection, 2/8 with partial resection, and 1/5 with no resection had local control with an overall 3-year actuarial survival of 32%. The local control and survival results in the primary tumors appear favorable compared to other series in the literature and suggest benefit to the use of IORT. For patients treated for local recurrence, local control and long-term survival can be obtained, but the results are not as encouraging as for the primary tumors.