Purpose: To determine whether positron emission tomography (PET) can help differentiate benign from malignant lesions of the salivary glands before surgery.
Materials and methods: Masses of the salivary glands were examined in 26 patients by means of computed tomography, magnetic resonance imaging, PET, biopsy (n = 18), and surgery. Contiguous PET scans were obtained from the midcranium to the lower chest 45 minutes after administration of 370 MBq (10 mCi) of fluorine-18 fluorodeoxyglucose (FDG). Standard uptake values (SUVs) were determined for all suspect lesions and for normal parotid glands and cerebellum.
Results: All lesions were visualized, and all but two showed some increase in FDG uptake. PET findings helped correctly differentiate benign from malignant masses in 18 (69%) but were false-positive for malignancy in eight (31%). SUV analysis, lesion-to-normal SUV ratios, and lesion-to-cerebellar SUV ratios also failed to differentiate the lesions.
Conclusion: FDG PET is not useful in classifying salivary gland tumors as benign or malignant.