PRIMARY OBJECTIVE:
I. To assess the optimal fludeoxyglucose F-18 (fluorodeoxyglucose) positron emission tomography (FDG PET) imaging time post radiotracer administration that maximizes separation of activity between lesion and non-lesional parenchyma (measured as lesion/background \[L/B\] ratio) in patients with brain metastasis.
SECONDARY OBJECTIVE:
I. To identify genotypic factors in FDG tumor metabolism derived from metrics, including maximum standard uptake value (SUVmax), mean standard uptake value (SUVmean), total lesion glycolysis (TLG), mean tumor volume (MTV), and L/B ratio.
EXPLORATORY OBJECTIVES:
I. To identify patterns of metabolism derived from metrics, such as SUVmax, SUVmean, TLG, MTV, and L/B ratio, and magnetic resonance imaging metrics, such as regional perfusion abnormalities, apparent diffusion coefficient values, fractional diffusivity measures, and magnetic resonance spectroscopic finding.
II. To identify if post treatment changes in lesion metabolism from baseline correlate with treatment success.
OUTLINE:
Patients receive fludeoxyglucose F-18 intravenously (IV) over approximately 1 minute and undergo a PET/MRI scan over 70 minutes. Within 5 hours of receiving fludeoxyglucose F-18, patients undergo a repeat PET/MRI scan over 30 minutes. Scans take place within 2 weeks before scheduled surgery and within 4-6 weeks after radiation treatment.
