HFSRT With Concurrent TMZ for Large BMs

Inclusion Criteria: * histologic or cytological diagnosis of primary tumor and conformed brain metastases by enhanced MRI or CT; * the number of BMs ≤ 3 * the tumor volume ≥6cc, or maximum diameter of BMs≥ 3cm; * Karnofsky performance score (KPS)≥60, or KPS≥40 but simply caused by BMs; * Age: 18-75 years old; * Adequate function of major organs, and blood test reached the following level: WBC≥4.0x109/L, NEU≥1.5x109/L Hemoglobin≥110 g/L, Platelets≥100 x109/L; Liver function test results\<1.5 times the institutional upper limit of normal (ULN); BUN and Cr: within the normal range. Exclusion Criteria: * patient with other clinically significant diseases (e.g. myocardial infarction within the past 6 months, severe arrhythmia); * unable or unwilling to comply with the study protocol; * patient whose survival expectancy was less than 3 months; * the large BM locates in brainstem; * patient who anticipated in other clinical trials of brain metastases; * the large lesions have been treated with SRT in other hospitals; * pregnant patients or female patients whose HCG is positive.