Inclusion Criteria:  Diagnosis of intracranial metastatic disease from solid malignancy that is amenable to and recommended for treatment with HA-WBRT by the treating physician. Patients may have had prior therapy for brain metastasis, including radiosurgery, prior whole brain RT, and surgical resection. Receipt of a contrast-enhanced brain MRI performed ≤21 days prior to study registration At least 18 years of age Karnofsky performance status ≥ 50 Able to understand and willing to sign an IRB approved written informed consent document (or that of legally authorized representative, if applicable)  Exclusion Criteria:  Pregnant and/or breastfeeding. Women of childbearing potential must have a negative pregnancy test within 14 days of study entry. If pregnancy test is not clinically indicated as determined by treating physician or protocol principal investigator (PI), documentation of this exception is sufficient in lieu of a pregnancy test.