Fluorodeoxyglucose positron emission tomography/CT for primary malignant intraosseous neoplasms of the mandible.

Primary intraosseous malignant neoplasm of the mandible is a very rare entity. There are few publications regarding fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT for primary intraosseous neoplasms of the mandible. FDG PET/CT scans from 10 patients with primary malignant neoplasm of the mandible were retrieved from the Picture Archiving and Communication System database, and image findings were analyzed with correlation to contrast-enhanced diagnostic CT and surgical pathology. Accuracy of the FDG PET/CT findings was evaluated with respect to uptake intensity, lesion extension to adjacent soft tissue, lymph node and distant metastasis. All untreated primary mandible neoplasms demonstrated high FDG avidity on PET imaging. Most mandible lesions extended beyond the bones and involved perimandibular soft tissue. FDG PET/CT imaging showed improved sensitivity and specificity compared with that for CT for lymph node staging in 3 cases, with discordant findings between diagnostic CT and PET/CT. FDG PET/CT identified 4 distant metastases, which were not documented prior to PET/CT. The results suggested that FDG PET/CT was a valuable image modality to demonstrate all primary and metastatic lesions of primary malignant neoplasm of the mandible, to define perimandibular soft tissue involvement, and more accurately stage/restage the disease than diagnostic CT.