Evaluation of Rare Tumors with [F-18]Fluorodeoxyglucose Positron Emission Tomography.

The purpose of this paper was to evaluate the utility of positron emission tomography (PET) with 2-[18F]fluoro-2-deoxy-D-glucose (FDG) in the clinical assessment of rare tumors. We identified 6 patients over the last 18 months with rare tumors who were referred for PET imaging at the time of initial diagnosis, for tumor surveillance or for posttherapy reevaluation. The PET findings were compared with follow-up clinical data, the results of other imaging modalities and histology. FDG PET correctly detected disease in patients with anaplastic thyroid cancer, pleural mesothelioma, myxoid liposarcoma, malignant fibrous histiocytoma, synovial cell sarcoma and uterine leiomyosarcoma. These findings suggest that PET is useful in the evaluation of a variety of rare tumors both for initial preoperative staging and post-therapy assessment. Further experience with other uncommon tumors is necessary to define the precise role of FDG PET in this clinical setting.