Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy with Intra-Operative Radiotherapy for Patients with Locally Advanced or Locally Recurrent Rectal Cancer and Peritoneal Metastases.

: To assess the safety and long-term outcome of a multimodality treatment consisting of radical surgery, intra-operative radiotherapy (IORT), and cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) for patients with locally advanced rectal cancer (LARC) or locally recurrent rectal carcinoma (LRRC) and peritoneal metastases (PM). : The present study was a single-center cohort study, including all consecutive patients undergoing this treatment in a tertiary referral center for LARC, LRRC, and PM. Postoperative complications, intensive care stay (ICU stay), and re-admission rates were assessed as well as disease-free survival (DFS) and overall survival (OS). : A total of 14 LARC and 16 LRRC patients with PM were included in the study. The median ICU stay was 1 day, and 57% of patients developed a severe postoperative complication. No 90-day mortality was observed. Median DFS was 10.0 months (Interquartile Range 7.1-38.7), and median OS was 31.0 months (Interquartile Range 15.9-144.3). : As postoperative complications and survival were in line with treatments that are accepted for LARC or LRRC and PM as separate procedures, we conclude that combined treatment with IORT and CRS-HIPEC should be considered as a treatment option for selected patients with LARC or LRRC and peritoneal metastases in tertiary referral centers.