Can surgeons predict the extent of abdominal surgery based on MRI findings in CRS-HIPEC candidates with colorectal cancer?

Introduction: Diffusion-weighted MRI (DW-MRI) is a promising tool for selecting patients with colorectal peritoneal metastases for cytoreductive surgery (CRS). This study investigated whether surgeons can predict the extent of CRS based on preoperative MRI findings. Methods: This single-centre retrospective study included patients who underwent CRS-HIPEC after preoperative MRI. An expert abdominal radiologist showed MR images to three experienced surgeons, who independently predicted the probability of achieving a complete resection by scoring which of 29 anatomical structures would be resected during CRS-HIPEC. Other predictions were surgery duration, number of anastomoses and CRS-HIPEC resulting in a stoma. Predictions were confirmed using surgical reports and histopathology. Results: Data from 29 patients were analyzed. The median surgical PCI was 6 [range 0-19]. Complete resection was achieved in all patients with a total of 216 structures resected. All three surgeons had a negative predicting value (NPV) above 75% for most anatomical structures, and a positive predicting value (PPV) ranging from moderate (50%-75%) to good (>75%). The PPV for CRS-HIPEC resulting in a stoma ranged between 71% and 100%, and for colon anastomoses between 57% and 77%. The ICC indicated good to excellent (>= 0.75) agreement among surgeons' predictions for most structures. Conclusion: Based on DW-MRI, the abdominal radiologist and surgeon are good at predicting the extent of the cytoreductive surgical procedure. Surgeons can use MRI findings for surgical planning and patient expectation management. However, adhesions and fibrosis interpreted as possible tumors during surgery and not clearly depicted small metastases on MRI can lead to more resections than anticipated.