Diagnostic Test Accuracy of 18F-FDG PET or PET/CT for Characterization of Histologic Type of Thymic Epithelial Tumor

Purpose This study investigated diagnostic accuracies of 18 F-FDG PET or PET/CT for characterization of histologic type of thymic epithelial tumors (TETs) through a systematic review and meta-analysis. Patients and Methods The PubMed, Cochrane database, and EMBASE database, from the earliest available date of indexing through August 31, 2020, were searched for studies evaluating diagnostic performance of 18 F-FDG PET or PET/CT for characterization of TET. We determined the sensitivities and specificities, calculated positive and negative likelihood ratios (LR+ and LR−), and constructed summary receiver operating characteristic curves. Results The pooled sensitivity of 18 F-FDG PET or PET/CT was 0.89 (95% confidence interval [CI], 0.80–0.95), and the pooled specificity was 0.77 (95% CI, 0.63–0.87) for differentiation between thymic cancer and thymoma. Likelihood ratio syntheses gave an overall positive likelihood ratio (LR+) of 3.9 and negative likelihood ratio (LR−) of 0.14. The pooled diagnostic odds ratio was 28 (95% CI, 13–63). The pooled sensitivity was 0.90 (95% CI, 0.75–0.96), and the pooled specificity was 0.81 (95% CI, 0.68–0.89) for differential diagnosis of a low-risk or high-risk TET. LR+ was 4.7 and LR− was 0.12. The pooled diagnostic odds ratio was 38 (95% CI, 12–121). In meta-regression analysis, no variable was the source of the study heterogeneity. Conclusions 18 F-FDG PET or PET/CT has excellent diagnostic performances for characterization of TET. Further large multicenter studies would be necessary to establish the diagnostic accuracy of 18 F-FDG PET or PET/CT for differentiation of histologic type of TET.