Performance of 18F-FDG PET/MR on TNM staging of pancreatic cancer compared with 18F-FDG PET/CT: A retrospective cohort study

Abstract

PurposeThis study aimed to evaluate the TNM staging accuracy of 18F-FDG PET/MR compared with 18F-FDG PET/CT in patients with pancreatic cancer. Materials and methodsIn this retrospective cohort study, a total of 88 patients (53 men, 35 women, mean age 64.56±10.77 years) with pathologically confirmed pancreatic cancer who underwent 18F-FDG PET/CT and 18F-FDG PET/MR successively on the same day were enrolled. The maximal and peak standardized uptake values (SUVmax and SUVpeak) of pancreatic cancer lesions on PET/MR and PET/CT imaging were measured respectively. According to the 8th edition AJCC staging system of pancreatic adenocarcinoma, two experienced readers reviewed and assessed the PET/CT and PET/MR images independently for TNM staging. Using the diagnosis of enhanced CT, histopathological diagnosis and/or the clinical follow-up as the reference, the diagnostic performance of PET/CT and PET/MR were compared using the McNemar test. ResultsCompared with 18F-FDG PET/CT (63.64%), 18F-FDG PET/MR (85.23%) exhibited significantly higher diagnostic accuracy of T staging (P<0.05). In N staging, the diagnostic accuracy of PET/MR (81.4%) was higher than that of PET/CT (74.42%) but the difference was not statistically significant. In M staging, no significant difference was found between the diagnostic performance of PET/MR (96.59%) and PET/CT (92.05%). However, PET/MR detected more liver metastases in 11/18 patients and the clinical staging was upstaged in four patients compared to PET/CT. Both SUVmax and SUVpeak of pancreatic tumors showed strong correlations between PET/MR and PET/CT imaging (r=0.901 and 0.923, respectively; P<0.05). ConclusionsCompared with 18FFDG PET/CT, 18FFDG PET/MR showed better performance in the TNM staging of pancreatic cancer, especially in T staging and detection of liver metastases.