18F-FDG and 18F-FDOPA PET Scan for the Diagnosis of Recurrent Brain Tumors

Inclusion Criteria

• Age >= 18
• Known or suspected recurrent malignant brain tumors
• Radiographic worsening reported on MRI shortly (within 3 months) after completion of radiation and temozolomide therapy
• Able to lie flat and/or still for a minimum of 60 minutes
• Willingness and ability to comply with scheduled visits and study procedures
• Patients who have a clinical indication for a PET-CT
• If female, patient must be postmenopausal or surgically sterile

Exclusion Criteria

• Conditions that preclude a clinical brain FDG PET study, including: * Consumption of liquids with sugar and/or caffeine prior to the study * Blood glucose levels over 150 mg/mL * Eating or drinking calories of any type within 4 hours of radiotracer injection * Hyperinsulinemia * Patients who for any reason cannot tolerate lying supine for 60 minutes
• Conditions that preclude a FDOPA PET study, including: * Consuming a diet that is NOT low in protein after the previous evening meal
• Tumor located in the striatum
• Changes in medication (new prescriptions or change in dosages) between visits 1 and 2
• Pregnant, nursing, or lactating
• Women of childbearing potential (premenopausal female capable of becoming pregnant), which also includes: * Women on oral, injectable, or mechanical contraceptives * Women who are single * Women whose male partners have been vasectomized or whose male partners have received or are utilizing mechanical contraceptive devices
• Weight > 450 pounds (lbs)
• Known allergic reactions to 3,4-dihydroxy-6-[18F]fluoro-L-phenylalanine (18F-FDOPA) and fluorine-18 fluorodeoxyglucose (18F-FDG)
• Confirmation that study eligibility criteria have not been met between visits 1 and 2