Preoperative irradiation and surgery for recurrent rectal cancer. Will intraoperative radiotherapy (IORT) be of additional benefit? A prospective study.

Background: The therapeutic gain of surgery for recurrent rectal cancer is not clear, particularly with regard to the addition of intraoperative radiotherapy (IORT).

Methods: Patients (107) with isolated pelvic recurrence of rectal cancer received preoperative external radiotherapy of 46-50 in 2 Gy fractions. At surgery 59 patients had IORT 12-18 Gy. Survival and local recurrence was analysed with regard to surgical resection stages and IORT.

Results: Patients (44) had R0- and 39 R1-resections, 24 R2-resections or exploratory laparotomy. IORT was given most often after R1-resections, least in R0-patients. Estimated 5-year survival was overall around 30%, around 60% in the R0-, around 25% for R1- and 0% in R2-patients. Local recurrence was around 30% in the R0- and around 65% in R1-stage patients. R0-/R1-stage patients survived statistically significantly longer than the R2-group otherwise there was no statistical significant difference between IORT and non-IORT groups in any R-stages regarding overall survival or local recurrence.

Conclusions: Macroscopic removal of the recurrence improves survival. Whether R0- is better than R1-resections is not clear. The effect of IORT is not a major one. IORT need be evaluated in randomised controlled trials.