FDG and FDOPA PET Demonstration of Functional Brain Abnormalities

PRIMARY OBJECTIVES: I. The primary objective will be to evaluate the diagnostic accuracy of Dynamic PET imaging in differentiating tumor recurrence from treatment effect (radiation necrosis or pseudoprogression) in patients previously treated with chemo-radiation therapy for primary high grade gliomas. This will be accomplished by examining the concordance between the Dynamic PET imaging prediction and the criterion standard, which will be based on either surgical pathology or an integrated clinical/MRI determination within a 3-6 month interval after Dynamic PET imaging. SECONDARY OBJECTIVES: I. The diagnostic accuracy of Static PET imaging, advanced MRI, and advanced MRI + Dynamic PET imaging in differentiating tumor recurrence from radiation-induced necrosis in high grade glioma patients will be examined in the same exact way as just outlined for Dynamic PET imaging. OUTLINE: Subjects receive 18FDG (first scan) and (18)F-FDOPA (2-14 days from the first scan) intravenously (IV) slowly over a period of 15-20 seconds and then undergo dynamic PET scans over a period of 60-90 minutes. CT scans on the subjects are performed before the dynamic PET scans for 5 minutes. Subjects also undergo MRI brain examinations just prior to the FDOPA scan over a period of 1 hour, which includes T1 weighed, T1 weighted contrast enhanced, T2 weighted, Diffusion tensor imaging, MR spectroscopy, and Dynamic susceptibility contrast perfusion weighted (DSC-PWI) imaging.