Clinical significance of parotid gland incidentalomas on 18F-FDG PET/CT

The aim of this study was to evaluate the frequency and clinical significance of incidental focal uptake of 18F-fluorodeoxyglucose (FDG) on positron emission tomography/computed tomography (PET/CT) in the parotid glands of cancer patients. A retrospective review of 7,252 oncologic PET/CT studies was done. FDG positive parotid incidentalomas occurred in 0.4% of PET/CT scans, of which only 4% were malignant. PET/CT was unable to differentiate benign from malignant parotid lesions based on SUVmax alone. 18F-FDG positive parotid incidentalomas can be managed conservatively, however patients with a prior history of lymphoma had a much higher risk of parotid malignancy and require further investigation.