PRIMARY OBJECTIVE:~I. To determine the static fluciclovine F18 (fluciclovine) PET imaging tumor-to-background ratios (TBRmax; TBRmean) which distinguish true tumor recurrence from radionecrosis in patients with intracranial metastatic disease previously treated with radiation therapy, and magnetic resonance imaging (MRI) findings suggesting recurrent disease, using histopathology as proof of disease.~SECONDARY OBJECTIVES:~I. To determine static fluciclovine PET standardized uptake value (SUV)peak, SUVmean values and metabolic tumor volumes (MTV) which distinguish true tumor recurrence from radionecrosis in patients with MRI findings suggesting recurrent disease, using serial MRI as a surrogate marker of disease.~II. To determine early dynamic fluciclovine PET time activity curve values which distinguish true tumor recurrence from radionecrosis in patients with MRI findings suggesting recurrent disease, using histopathology or serial MRI as a marker of disease.~III. To correlate the determined static fluciclovine PET SUVpeak, SUVmean, TBRmax, TBRmean, and MTV values with progression free survival.~IV. In patients with true tumor progression, SUV values will be correlated with Ki67 staining on final pathology.~OUTLINE:~Patients receive fluciclovine intravenously (IV) and undergo brain dynamic PET/MRI imaging over 50 minutes.~After completion of study, patients are followed up every 3 months for up to 1 year.
This phase I trial studies the ability and amount of fluciclovine positron emission tomography (PET) imaging needed to recognize tumors that have come back (recurrence) after brain injury from radiation therapy (radionecrosis) in patients with intracranial disease that has spread to other places in the body (metastatic). F-18 fluciclovine is a radiotracer that works by accumulating in tumor cells, making it easier to detect tumors. The results of this study may also help investigators understand all the ways that F-18 fluciclovine may affect patients.