Purpose To further define anatomic criteria for resection and ablation using an expert panel-based three-dimensional liver model to objectively predict local treatment recommendations for colorectal liver metastases (CRLM). Materials and Methods This study analyzed data from participants with small CRLM (≤3 cm) considered suitable for resection, thermal ablation, or irreversible electroporation (IRE), according to a multidisciplinary expert panel, who were included in two prospective multicenter trials (COLLISION [NCT03088150] and COLDFIRE-2 [NCT02082782]) between August 2017 and June 2022. Ten randomly selected participants were used to standardize the model's Couinaud segments. CRLM coordinates were measured and plotted in the model as color-coded lesions according to the treatment recommendations. Statistical validation was achieved through leave-one-out cross-validation. Results A total of 611 CRLM in 202 participants (mean age, 63 [range, 29-87] years; 138 male and 64 female) were included. Superficially located CRLM were considered suitable for resection, whereas more deep-seated CRLM were preferably ablated, with the transition zone at a subsurface depth of 3 cm. Ninety-three percent (25 of 27) of perihilar CRLM treated with IRE were at least partially located within 1 cm from the portal triad. Use of the model correctly predicted the preferred treatment in 313 of 424 CRLM (73.8%). Conclusion The results suggest that CRLM can be defined as superficial (preferably resected) and deep-seated (preferably ablated) if the tumor center is within versus beyond 3 cm from the liver surface, respectively, and as perihilar if the tumor margins extend to within 1 cm from the portal triad. Keywords: Ablation Techniques, CT, MRI, Liver, Abdomen/GI, Metastases, Oncology Supplemental material is available for this article. © RSNA, 2024.
Keywords: Abdomen/GI; Ablation Techniques; CT; Liver; MRI; Metastases; Oncology.