Intraoperative radiation therapy for patients with recurrent rectal and sigmoid colon cancer in previously irradiated fields.

A retrospective study evaluated 15 patients with pelvic recurrence of colorectal cancer in a previously irradiated region who received intraoperative radiation therapy (IORT) as part of salvage therapy. Total prior external beam radiation therapy (EBRT) doses ranged from 45 to 79.2 Gy. Tumor resection was accomplished in 14 patients, with an exenteration performed in seven. IORT dose was 15-20 Gy. Three patients received additional EBRT as a post-operative course of 25.2 Gy in 14 fractions. Actuarial 3-year local control rate was 25%. The 3-year overall survival rate was 29%. Patients with fixed and/or bulky pelvic tumors had a local control rate of 19% at 12 months and median overall survival of 9 months. Patients with less extensive clinical presentations of anastomotic non-fixed transmural recurrence, isolated pelvic node metastasis and rectal recurrence following local excision had a local control rate of 42% at 36 months and median survival of 43 months. We conclude that clinical presentation of recurrent disease is an important prognostic factor. The value of IORT may be limited to patients with less extensive clinical presentations.