Positron Emission Tomography (PET) With 3,4-dihydroxy-6-18F-fluoro-L-enylalanine (18F-FDOPA) Study

Inclusion Criteria: * Contrast-enhancing mass on diagnostic brain CT or MRI strongly suggesting a diagnosis of WHO grade III or IV glioma * Karnofsky Performance status (KPS) ≥ 70 * Age ≥18 years * Subject is able to understand and consent to study * Glomerular filtration rate (GFR) ≥ 45 ml/minute Exclusion Criteria: * Indication for urgent craniotomy to relieve mass effect * Only stereotactic biopsy indicated because tumour is located in eloquent brain. * The enhancement on the T1 MRI sequence involves or abuts the basal ganglia * Previous intracranial malignancy or any invasive malignancy unless free of disease \> 5 years * Prior cranial irradiation * Contra-indications to systemic radiation exposure: pregnancy or breast feeding * Subject exceeds the weight limit of the PET scanner bed (204.5 kg) * Subjects taking medication such as Levodopa for the treatment of Parkinson's Disease * Allergies or other contraindication to CT contrast or MRI contrast