Stereotactic Radiation for Growing/Changing Brain Metastases With Same-Day Radiation Planning and Treatment With Margin Reduction

This study is testing whether stereotactic radiosurgery (a very precise form of radiation) can safely treat brain metastases that are growing quickly or are in a concerning location — rather than waiting or using whole-brain radiation. It is for people whose cancer has spread to the brain from another part of the body. **You may be eligible if...** - You are 18 or older - You have a solid cancer that has spread to the brain (brain metastases), confirmed by biopsy or imaging - Your brain metastasis is growing at least 1mm per week, is near a swollen area of the brain, or is close to a recent surgical cavity - You are in reasonably good functional health (Karnofsky score of at least 60) - Your doctor expects you to live at least 3–6 more months **You may NOT be eligible if...** - Your overall health condition makes radiation treatment unsafe - You are unable to complete the required assessments or follow-up Talk to your doctor to see if this trial is right for you.