Predictors of pathologic outcome of focal FDG uptake in the parotid gland identified on whole-body FDG PET imaging

PurposeThe purpose was to test whether patient’s primary malignancy type and presence of F-18-fluorodeoxyglucose (FDG)-avid cervical lymph node(s) are predictors of pathologic outcome of incidental focal FDG-avid parotid lesions.Basic proceduresA retrospective cohort study of pathologically proven incidental cases was performed.Main findingsFocal parotid FDG uptake in the setting of head and neck cancer/melanoma [odds ratio (OR)=24.6, P< .01], lymphoma (OR=7.2, P= .02), or FDG-avid cervical lymph node(s) (OR=3.6, P= .07) has a higher odds of representing metastases. No malignant primary parotid tumors were incidentally discovered.Principal conclusionsIn patients with head and neck cancer/melanoma, lymphoma, or FDG-avid cervical lymph node(s), there were higher odds that focal parotid FDG uptake was a metastasis.