Intraoperative irradiation after surgery for locally recurrent rectal cancer.

PURPOSE: This study retrospectively evaluated the effects of intraoperative electron beam irradiation on patients with locally recurrent (pelvic) rectal cancer.
METHODS: From November 1, 1975, to December 31, 1997, 51 patients underwent surgery for locally recurrent rectal or rectosigmoid cancer, and 27 patients received intraoperative electron beam irradiation. The intraoperative electron beam irradiation dose was 15 to 30 Gy. Kaplan-Meier survival estimates at three and five years were analyzed for the 47 patients who recovered postoperatively.
RESULTS: Statistically significant factors related to survival included intraoperative electron beam irradiation vs. no intraoperative electron beam irradiation (P=0.0007), amount of residual tumor (slight vs. gross; P=0.0022), and symptom status (P=0.0024). Factors not associated with survival included distant metastases at reoperation, type of surgery for the recurrent tumor, external beam irradiation, pathologic grade, age, and gender. Surgical resection without intraoperative electron beam irradiation resulted in three-year and five-year survival rates of 5 and 0 percent, respectively. For patients who received intraoperative electron beam irradiation, the three-year survival rate was 43 percent and five-year survival rate was 21 percent. Intraoperative electron beam irradiation was a statistically significant factor related to survival in patients with and without distant metastasis (P=0.04 and P=0.0035, respectively), with slight residual tumor (P=0.0003), or with palliative surgery (P=0.0276).
CONCLUSION: The trends seen in resection with intraoperative electron beam irradiation are encouraging with regard to improvements in survival as compared with studies not using intraoperative electron beam irradiation treatment.