Evaluation of 18F-fluciclovine (FACBC) PET/MR Uptake in Participants With Glioma

This is a pilot study to assess the ability of \[F-18\]fluciclovine to differentiate pseudoprogression from progression in participants after therapy, at imaging time points within the 12 week interval post chemoradiation. \[F-18\]fluciclovine. PET will be obtained at the time point in the 12 week interval in which MRI demonstrates increase in enhancing volume with the differential diagnosis of pseudoprogression versus tumor progression. At the same time point (at least 6 hours after \[F-18\]fluciclovine or up to 3 days) F-18 FDG will also be performed consistent with standard clinical practice. The verification of pseudoprogression versus tumor progression will be determined by the regression of enhancing lesion on subsequent MRI imaging obtained as part of standard care.