Abstract
1687
Objectives: We evaluated the uptake of 2-deoxy-2-18F-fluoro-d-glucose (FDG) and l-[methyl-11C]-methionine (MET) in patients with newly diagnosed intracranial meningioma and correlated the results with tumor grade and proliferation. MATERIALS AND METHODS. Data from 22 patients with newly diagnosed intracranial meningioma (12 grade I and 10 grade II) who underwent both FDG and MET brain PET/CT studies were retrospectively analyzed. The PET images were evaluated by a qualitative method and semiquantitative analysis using standardized uptake value (SUV) and tumor-to-normal (T/N) ratio. Proliferative activity as indicated by the Ki-67 index was estimated in tissue specimens. RESULTS. MET PET/CT showed a higher detection rate of meningioma than did FDG PET/CT (100 vs. 46 %). The T/N ratio of MET was significantly higher than that of FDG (p < 0.001). There was a significant difference in FDG SUV(p < 0.003), FDG T/N ratio (p < 0.006), MET SUV(p < 0.002), and MET T/N ratio (p < 0.002) between grades I and II. There was a significant correlation between FDG and Ki-67 index for SUV (p < 0.02) and for T/N ratio (p < 0.03) and between MET and Ki-67 index for SUV (p < 0.004) and for T/N ratio (p < 0.004).
Conclusions: MET PET/CT showed a high sensitivity compared with FDG PET/CT for the detection of newly diagnosed intracranial meningioma. Although both FDG and MET uptake was found to be useful for evaluating tumor grade and proliferation in meningioma, the correlation observed for MET uptake was better than that observed for FDG uptake.