Pilot Phase 2 Study Whole Brain Radiation Therapy With Simultaneous Integrated Boost for Patients With Brain Metastases

Primary Objective Evaluate two de-escalated whole brain radiation dose levels (in the setting of simultaneous integrated boost to gross lesions) with respect to in-brain distant control for brain metastases, defined as an in-brain failure rate outside of the planning target volume at 6 months of \< 20%. Secondary Objectives 1. Evaluate treated lesion control at 6 months for brain metastases in the setting of a predetermined total biologically effective SIB dose as determined by radiographic progression within the planning target volume with fusion and overlay of follow-up MRIs. 2. Evaluate overall survival at 6 months for brain metastases in the setting of WBRT with SIB. 3. Evaluate changes in neurocognitive function after WBRT with SIB in the following domains: verbal learning and memory as assessed by the Hopkins Verbal Learning Test - Revised (HVLT-R). 4. Evaluate changes in health-related quality of life as assessed by the Functional Assessment of Cancer Therapy with Brain Subscale (FACT-Br) after WBRT-SIB for brain metastases. 5. Evaluate changes in performance status as assessed by the Karnofsky Performance Status tool after WBRT-SIB for brain metastases. 6. Evaluate adverse events after WBRT-SIB for brain metastases according to current CTCAE criteria.