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

Inclusion Criteria: 1. Participants must have a biopsy proven solid malignancy with at least one intact, residual or recurrent, intracranial lesion radiographically consistent with or pathologically proven to be a brain metastasis meeting one of the following criteria: 1. Growth of 1.0mm per week or more, on average, based on the two most recent brain MRIs preceding study enrollment 2. Abutment, to within 1.0cm, of a region of intracranial edema 3. Proximity (within 5.0cm) to a surgical cavity created within 30 days of enrollment 4. Proximity (within 5.0cm) to another source of physical displacement 2. Age of at least 18 years 3. Karnofsky performance status of at least 60 4. Estimated survival of at least 3-6 months in the opinion of the enrolling clinician and/or study PI 5. Ability to understand and the willingness to sign a written informed consent document by either ink on paper or a DF/HCC approved eConsent medium Exclusion Criteria: 1. Participants who cannot tolerate a brain MRI 2. Patients who cannot receive gadolinium 3. Participants with end stage renal disease 4. Participants with widespread, definitive leptomeningeal disease 5. Pregnant women are excluded from this study because of the potential deleterious effects of gadolinium on the developing fetus. Because there is an unknown but potential risk for adverse events in nursing infants, women who are breastfeeding are not eligible for this study as well