Fluorine-18 fluorodeoxyglucose positron emission tomography imaging of parotid mass lesions

Using X-ray CT or magnetic resonance imaging (MRI), fluorine-lb fluorodeoxy glucose (FDG) positron emission tomography (PET) studies were performed in 28 patients with parotid lesions. All lesions except two showed higher accu mulation of FDG than normal parotid gland. High accumulation was found in a ll of 5 carcinomas, all of 6 Warthin's tumors, and 8 of 12 pleomorphic aden omas, with standardized uptake values (SUVs) over 3.0. The mean SWs of carc inomas, Warthin's tumors, and pleomorphic adenomas were 5.92 +/- 2.05, 7.03 +/- 2.49, and 4.07 +/- 1.55, respectively. On the other hand, all 5 inflam matory lesions demonstrated low accumulation, with mean SUVs of 1.66 +/- 0. 89. It is thus difficult to differentiate malignant from benign parotid les ions by SUV on FDG-PET.