RecruitingPhase 2Drug trialProspective Evaluation Of High-Dose Systemic Methotrexate In Patients With Breast Cancer And Leptomeningeal MetastasisThis study is a prospective evaluation of systemic, intravenous high-dose methotrexate (HD-MTX, 8 g/m2) in patients with triple negative, HER2-positive, and hormone refractory breast cancer with leptomeningeal metastasis (LMD) with or without brain parenchymal involvement.