Brain MRI Surveillance for Stage IV Breast Cancer

Inclusion Criteria: * Histologic diagnosis of breast cancer with documentation of ER/PR/HER2 status * Radiographic evidence of stage IV extracranial disease enrolled within 60 days of diagnosis or starting first line therapy. HR+/HER2- patients may be enrolled within 60 days of starting 2nd line therapy as well. * HR+ will be defined as ER and/or PR \> 10%. To be classified as HER2+ disease, overexpression of HER2 by either IHC or in-situ hybridization is necessary as defined by the ASCO / CAP Guidelines41. Triple negative will be classified as ER and PR \<10% and HER2-. * Age ≥ 18 * Life expectancy ≥ 6 months * Eastern Cooperative Oncology Group performance status ≤ 2 * Patients must be able to understand and the willingness to sign an informed consent for study procedures * Stated willingness to comply with all study procedures and availability for the duration of the study Exclusion Criteria: * Prior diagnosis or treatment of brain metastases or leptomeningeal disease * History of other non-breast malignancy requiring treatment with the exception of those with a negligible risk of metastasis or death (e.g., 5-year OS of \> 90%), such as but not limited to, non-melanoma skin cancers, stage I endometrioid uterine cancer, and others at the discretion of the PI * Neurologic symptoms warranting standard screening brain MRI in the judgement of the treating physician at time of enrollment * Indications warranting brain MRI for other neurologic conditions at time of study entry (including multiple sclerosis, stroke, traumatic brain injuries, epilepsy, hydrocephalus and pituitary gland disorders) * Contraindication towards MRI with contrast * Chronic kidney disease stage IV or V or end stage renal disease (CrCl \<30 ml/min)