Evaluating agreement regarding the resectability of colorectal liver metastases: a national case-based survey of hepatic surgeons

Background: The resectability of colorectal liver metastases is in part largely based on the surgeon's assessment of cross-sectional imaging. This process, while guided by principles, is subjective. The objective of the present study was to assess agreement between hepatic surgeons regarding the resectability of colorectal liver metastases. Methods: Forty-six hepatic surgeons across Canada were invited. A patient with biologically favourable disease was presented after having received neoadjuvant chemotherapy. The scenario was matched with 10 different scrollable abdominal CT scans representing a maximum response after six cycles of chemotherapy. Surgeons were asked to offer an opinion on resectability of liver metastases, and whether they would use adjunct modalities to hepatic resection. Results: Twenty-six surgeons participated. Twenty responses were complete. The median number of scenarios deemed resectable was 6/10 (range 3-8). Two control scenarios demonstrated perfect agreement. Agreement on resectability was poor for 4/8 test scenarios, of which one scenario demonstrated complete disagreement. Among resectable cases, the pattern of use of adjunct modalities was variable. A median ratio of 0.87 adjunct modality per resectable scenario per surgeon was used (range 0.25-1.75). Conclusion: A significant lack of agreement was identified among surgeons on the resectability and use of adjunct modalities in the treatment of colorectal liver metastases.