18F-Fluciclovine PET Amino Acid Evaluation of Brain Metastasis Treated With Stereotactic Radiosurgery

This study tests whether a specialized type of PET scan (using a tracer called 18F-Fluciclovine that targets amino acid uptake) can better evaluate brain metastases before and after stereotactic radiosurgery (SRS) — a precise, highly focused radiation treatment. Better imaging may help doctors tell the difference between tumor growth and radiation side effects. **You may be eligible if...** - You have cancer that has spread to the brain (brain metastases) - All brain lesions are 2 cm or smaller - You are scheduled to receive stereotactic radiosurgery (SRS) - You are in good enough health (ECOG 0–2) **You may NOT be eligible if...** - You have had a prior severe allergic reaction to 18F-Fluciclovine (the scan tracer) - There is evidence of cancer spreading along the lining of the brain (leptomeningeal disease) - You have previously received whole-brain radiation - You cannot undergo MRI safely Talk to your doctor to see if this trial is right for you.