Diagnostic value of 18F-FDG PET/MRI for staging in patients with ovarian cancer

Abstract Purpose: To evaluate the diagnostic potential of PET/MRI with 18F-fluorodeoxyglucose (18F-FDG) in ovarian cancer.Materials and Methods: Participants comprised 103 patients with suspected ovarian cancer underwent pretreatment 18F-FDG PET/MRI, contrast-enhanced CT (ceCT) and pelvic dynamic contrast-enhanced MRI (ceMRI). Diagnostic performance of 18F-FDG PET/MRI and ceMRI for assessing the characterization and the extent of the primary tumor (T stage) and 18F-FDG PET/MRI and ceCT for assessing nodal (N stage) and distant (M stage) metastases was evaluated by two experienced readers. Histopathological and follow-up imaging results were used as the gold standard. The McNemar test was employed for statistical analysis.Results: Accuracy for the characterization of suspected ovarian cancer was significantly better for 18F-FDG PET/MRI (92.5%) [95% confidence interval (CI) 0.841–0.950] than for ceMRI (80.6%) (95%CI 0.715–0.830) (p <0.05). Accuracy for T status was 96.4% (95%CI 0.964–0.964) and 92.9% (95%CI 0.929–0.929) for 18F-FDG PET/MRI and ceMRI/ceCT, respectively. Patient-based accuracies for N and M status were 100% (95%CI 0.883–1.000) and 100% (95%CI 0.884–1.000) for 18F-FDG PET/MRI and 85.2% (95%CI 0.758–0.852) and 30.8% (95%CI 0.188–0.308) for ceCT and M staging representing significant differences (p<0.01). Lesion-based sensitivity, specificity and accuracy for N status were 78.6% (95%CI 0.571–0.913), 95.7% (95%CI 0.932–0.972) and 93.9% (95%CI 0.893–0.966) for 18F-FDG PET/MRI and 42.9% (95%CI 0.240–0.581), 96.6% (95%CI 0.943–0.984) and 90.8% (95%CI 0.868–0.941) for ceCT. Conclusions: Use of 18F-FDG PET/MRI offers better sensitivity and specificity for the characterization and M staging than ceMRI and ceCT, and diagnostic value for T and N staging equivalent to ceMRI and ceCT, suggesting that 18F-FDG PET/MRI might represent a useful diagnostic alternative to conventional imaging modalities in ovarian cancer.