F-18-FDG PET/MRI vs MRI in patients with recurrent adenoid cystic carcinoma

Objectives To evaluate and compare the diagnostic potential of F-18-fluorodeoxyglucose positron emission tomography/magnetic resonance imaging ((18)FDG-PET/MRI) and MRI for recurrence diagnostics after primary therapy in patients with adenoid cystic carcinoma (ACC). Methods A total of 32 dedicated head and neck F-18-FDG PET/MRI datasets were included in this analysis. MRI and F-18-FDG PET/MRI datasets were analyzed in separate sessions by two readers for tumor recurrence or metastases. Results Lesion-based sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy were 96%, 84%, 90%, 93%, and 91% for F-18-FDG PET/MRI and 77%, 94%, 95%, 73%, and 84% for MRI, resulting in a significantly higher diagnostic accuracy of F-18-FDG PET/MRI compared to MRI (P < .005). Conclusion F-18-FDG PET/MRI is superior to MRI in detecting local recurrence and metastases in patients with ACC of the head and neck. Especially concerning its negative predictive value, F-18-FDG PET/MRI outperforms MRI.