Feasibility of Routine Application of Gadoxetic Acid-Enhanced MRI in Combination with Diffusion-Weighted MRI for the Preoperative Evaluation of Colorectal Liver Metastases.

Abstract

Gadoxetic acid-enhanced magnetic resonance imaging (MRI) in combination with diffusion-weighted MRI (Gd-EOB-MRI/DWI) has become popular for evaluating colorectal liver metastases (CRLM). This retrospective observational study aimed to determine whether this procedure should be indicated prior to hepatectomy in all patients with CRLM. A retrospective survey of relevant data of patients who had undergone hepatectomy for CRLM from 2008 to 2014 was performed. The rates of detection by contrast-enhanced computed tomography (CE-CT) and Gd-EOB-MRI/DWI were evaluated. In addition, relapse-free and overall survivals after primary hepatectomy were compared between patients who had undergone only CE-CT versus those who had undergone both CE-CT and Gd-EOB-MRI/DWI. In all, 419 pathologically confirmed CRLM were resected in 202 hepatectomies in 177 patients. The sensitivity of detection of CRLM was 77% for CE-CT and 93% for Gd-EOB-MRI/DWI (P<0.01). The sensitivity of detection of 1-5, 6-10, and 11-15mm CRLM by CE-CT was 9.6% (5/52), 47% (26/55), and 76% (57/75), respectively, whereas that by Gd-EOB-MRI/DWI was 54% (28/52), 91% (50/55), and 99% (74/75), respectively; these differences are significant (P<0.01 for all three groups). Relapse-free (P=0.99) and overall survival (P=0.79) did not differ significantly between 37 patients evaluated preoperatively by only CE-CT and 168 patients evaluated by both CE-CT and Gd-EOB-MRI/DWI. Gd-EOB-MRI/DWI detects small CRLM (≤15mm) with higher sensitivity than CE-CT. However, whether Gd-EOB-MRI/DWI should be a routine component of preoperative evaluation remains unclear in terms of survival benefit.