Diffusion-weighted MRI versus FDG-PET/CT for diagnosing pancreatic cancer: an indirect comparison meta-analysis

Background Fluorodeoxyglucose positron emission tomography (FDG-PET)/computed tomography (CT) and diffusion-weighted magnetic resonance imaging (DWI or DW-MRI) are tools for the diagnosis of pancreatic cancer. However, comparison of their diagnostic performance remains unknown. Purpose To indirectly compare the diagnostic value of DWI and FDG-PET/CT in the detection of pancreatic cancer. Material and Methods A literature search of PubMed, Embase, and Cochrane Library electronic databases for articles published through May 2018 yielded 875 articles. For the meta-analysis, we included 26 studies evaluating the efficacy of DWI and FDG-PET/CT for determining pancreatic cancer with a total of 1377 patients. QUADAS (Quality Assessment of Diagnostic Accuracy Studies) was used to assess the study quality. Sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and the area under the receiver operating characteristic curves (AUC) with their 95% confidence intervals were calculated for each individual study. Results There were no significant differences between DWI and FDG-PET/CT for sensitivity, specificity, PLR, NLR, or DOR, while DWI AUC was higher than that of FDG-PET/CT for the detection of pancreatic cancer. Conclusion The diagnostic value of both DWI and FDG-PET/CT were comparable and, hence, both techniques seem to be equally useful tools for the diagnosis of pancreatic cancer.