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. (c) RSNA, 2018