Preoperative Assessment of Pancreatic Cancer with FDG PET/MR Imaging versus FDG PET/CT Plus Contrast-enhanced Multidetector CT: A Prospective Preliminary Study.

Purpose To determine the diagnostic performance of fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET)/magnetic resonance (MR) imaging in the preoperative assessment of pancreatic cancer in comparison with that of FDG PET/computed tomography (CT) plus contrast material-enhanced multidetector CT. Materials and Methods This prospective study was approved by the institutional review board; written informed consent was obtained. Thirty-seven patients with 39 pancreatic tumors underwent preoperative FDG PET/MR imaging, PET/CT, and contrast-enhanced multidetector CT. The authors measured maximal and mean standardized uptake values (SUV _max and SUV _mean , respectively) of pancreatic cancer at PET/MR imaging and PET/CT. Two radiologists independently reviewed the two imaging sets (set 1, PET/MR imaging; set 2, PET/CT plus multidetector CT) to determine tumor resectability according to a five-point scale, N stage (N0 or N positive), and M stage (M0 or M1). With use of clinical-surgical-pathologic findings as the standard of reference (n = 20), diagnostic performances of the two imaging sets were compared by using the McNemar test. Results Both SUV _max and SUV _mean of pancreatic tumors showed strong correlations between PET/MR imaging and PET/CT (r = 0.897 and 0.890, respectively; P < .001). The diagnostic performance of PET/MR imaging was not significantly different from that of PET/CT plus multidetector CT in the assessment of tumor resectability (area under the receiver operating characteristic curve: 0.891 vs 0.776, respectively, for reviewer 1 [P = .109] and 0.859 vs 0.797 for reviewer 2 [P = .561]), N stage (accuracy: 54% [seven of 13 patients] vs 31% [four of 13 patients]; P = .250 for both reviewers), and M stage (accuracy: 94% [16 of 17 patients] vs 88% [15 of 17 patients] for reviewer 1 [P > .999] and 94% [16 of 17 patients] vs 82% [14 of 17 patients] for reviewer 2 [P = .500]). Conclusion FDG PET/MR imaging showed a diagnostic performance similar to that of PET/CT plus contrast-enhanced multidetector CT in the preoperative evaluation of the resectability and staging of pancreatic tumors. ^© RSNA, 2016 Online supplemental material is available for this article.