Pancreatic Ductal Adenocarcinoma: Rim Enhancement at MR Imaging Predicts Prognosis after Curative Resection.

Purpose To identify features at preoperative magnetic resonance (MR) imaging that could predict favorable prognosis after curative resection of pancreatic ductal adenocarcinoma (PDAC). Materials and Methods From January 2009 to December 2014, this retrospective study included 143 patients with surgically resected (ie, R0) PDAC who underwent preoperative MR imaging within 1 month before surgery. Clinical-pathologic and MR imaging findings for predicting disease-free survival (DFS) and overall survival (OS) were identified by using a Cox proportional hazards model. Important MR imaging features were compared with clinical-pathologic findings. Results Tumor size at histopathologic analysis was associated with both DFS and OS (hazard ratio per centimeter, 1.37; 95% confidence interval: 1.15, 1.63; P < .001 and hazard ratio, 1.44; 95% confidence interval: 1.20, 1.73; P < .001, respectively). Rim enhancement at dynamic contrast material-enhanced MR imaging was associated with significantly worse DFS and OS (hazard ratio, 1.72; 95% confidence interval: 1.05, 2.82; P = .030 and hazard ratio, 2.27; 95% confidence interval: 1.39, 3.69; P = .001, respectively). Diffusion-weighted imaging parameters, including diffusion restriction and apparent diffusion coefficient value, did not predict DFS or OS after resection of PDAC (all P > .05). Rim-enhancing lesions had more aggressive histologic tumor grades, less frequent remaining acini, and more frequent necrosis within the tumor compared with non-rim-enhancing pancreatic lesions (P = .002, P = .008, and P < .001, respectively). Conclusion Greater tumor size and rim enhancement were associated with lower DFS and OS rates after attempted curative resection of PDAC. © RSNA, 2018 Online supplemental material is available for this article.