FSRT in Breast Cancer Patients With Brain Metastases

Inclusion Criteria: * Histologically confirmed HER2 positive advanced breast cancer * Age\>18 years. * 1 to 10 brain metastases confirmed by enhanced brain MRI * KPS≥70 * Life expectancy of more than 12 weeks * Prior therapy of oral dexamethasone not exceeding 16mg/d * Time interval from prior therapy was more than 2 weeks, and evaluation of adverse events is no more than grade 1. * Maximum diameter of intracranial metastases is less than 3cm measured by enhanced brain MRI(2-3mm) * Prior endocrine therapy were allowed * Anti-Her2 targeted treatment were allowed * Screening laboratory values must meet the following criteria( and should be obtained within 28 days prior to registration): Absolute Neutrophil Count (ANC) ≥ 1.5 x 109/L, Platelets≥ 90 x 109/L, Hemoglobin ≥ 90 g/L Aspartate aminotransferase/alanine aminotransferase (AST/ALT) ≤2.5 x ULN without liver metastasis,≤ 5 x ULN with liver metastases Serum BUN and creatinine ≤ 1.5 x Upper Limit of Normal (ULN) * Time interval from chemotherapy was more than 2 weeks, endocrine therapy and anti-Her2 targeted treatment are allowed to be used concurrently with FSRT * Signed the informed consent form prior to patient entry Exclusion Criteria: * Leptomeningeal or hemorrhagic metastases * Uncontrolled epilepsy * Severe complication: cardiovascular disease, end-stage renal disease, severe hepatic disease, infection etc. * Pregnancy or lactation period， women of child-bearing age who are unwilling to accept contraceptive measures. * Inability to complete enhanced MRI * Patients who are difficult or unable to be followed-up * Not suitable for inclusion for specific reasons judged by sponsor * Patients who are receiving cytotoxic drug concomitantly * Have received prior radiotherapy for brain metastasis