Diagnostic value of PET/CT versus PET/MRI in gynecological malignancies of the pelvis: A meta-analysis

Purpose: To perform a meta-analysis of the literature to compare the diagnostic performance of 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) versus 18F-FDG positron emission tomography/magnetic resonance imaging (PET/MRI) for gynecological malignancies of the pelvis. Materials and methods: We searched for English-language studies, published through May 2019, on the diagnostic accuracy of PET/CT and PET/MRI for gynecological malignancies. To reduce inter-study heterogeneity, we focused primarily on studies in which both PET/CT and PET/MRI were performed on the entire study cohort. We pooled the sensitivity, specificity, diagnostic odds ratio, and area-under-the-receiver-operating-characteristic curve values for PET/CT and PET/MRI and determined the 95% confidence intervals (CIs). Results: Out of 30 studies, nine met the inclusion criteria. On patient-based analysis, PET/CT had a pooled sensitivity and specificity of 62.6% (95% CI: 47.1%-76%) and 91.6% (95% CI: 81.9%-96.3%), respectively, compared with 73.3% (95% CI: 63.1%-81.6%) (P = 0.22) and 91.2% (95% CI: 81.8%-96%) (P = 94) for PET/MRI. On lesion-based analysis, PET/CT had a pooled sensitivity and specificity of 81.5% (95% CI: 59.3%-93.1%) and 86.6% (95% CI: 77.3%-92.5%), respectively, compared with 84.7% (95% CI: 66.8%-93.8%) (P = 0.77) and 89.3% (95% CI: 85.2%-92.3%) (P = 0.51) for PET/MRI. The diagnostic odds ratios for PET/CT compared with PET/MRI were not significantly different in the patient-based (P = 0.48) and lesion-based analyses (P = 0.4). Conclusion: Compared with PET/CT, PET/MRI had slightly better diagnostic performance to that of 18F-FDG PET/CT in the gynecological malignancies on lesion level (44 vs 26) and patient level analysis (28 vs 17). However, the differences between results showed no statistical significance (P = 0.4 and 0.48, respectively).