NEUROBLASTOMA - POSITRON EMISSION TOMOGRAPHY WITH 2-[FLUORINE-18]-FLUORO-2-DEOXY-D-GLUCOSE COMPARED WITH METAIODOBENZYLGUANIDINE SCINTIGRAPHY

PURPOSE: To assess the uptake in neuroblastoma of 2-[fluorine-18]-fluo ro-2-deoxy-D-glucose (FDG) versus metaiodobenzylguanidine (MIBG). MATE RIALS AND METHODS: Seventeen patients with known or suspected neurobla stoma underwent FDG positron emission tomography (PET) (20 scans) and MIBG scintigraphy. Tumor uptake of FDG was quantified on positive FET scans. RESULTS: Tumor uptake of FDG was detected in 16 of 17 patients (18 of 20 scans). Neuroblastomas and their metastases avidly concentra ted FDG prior to chemotherapy or radiation therapy. Uptake after thera py was variable. Uptake of FDG was intense in one patient with neurobl astoma that failed to accumulate MIBG. In 13 of the 20 scans, however, MIBG was rated superior to FDG for delineation of tumor compared with background and normal organs. CONCLUSION: Most neuroblastomas accumul ate FDG. The mechanism of MIBG uptake is more intense prior to therapy . Concentration of FDG is not dependent on type 1 catecholamine uptake . FDG PET helps define the distribution of neuroblastomas that fail to concentrate MIBG.