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

SIMPLE SUMMARY: Although relatively rare, locally advanced or recurrent rectal cancer (LARC and LRRC) can metastasize. Patients whose advanced rectal cancer has metastasized to the peritoneum face a very poor prognosis. In selected patients, the prognosis might be improved by undergoing very intense treatment. This multimodality treatment, consisting of intraoperative radiotherapy (IORT), cytoreductive surgery, and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC), is aimed at attaining a microscopic radical resection of the rectal tumor and its peritoneal metastases (PM), as this is the only option for long-term survival. The present study reports on 30 consecutive patients who have undergone this multimodality treatment. The results in terms of complications and survival are comparable to the results described in the literature on IORT and CRS-HIPEC as separate treatment entities. Thus, this multimodality treatment can be considered a treatment option for highly selected patients, provided that it is performed in a tertiary referral center. ABSTRACT: Purpose: 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). Methods: 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). Results: 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). Conclusions: 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.