Bevacizumab Combined With Fractionated Stereotactic Radiotherapy for 1 to 10 Brain Metastases From NSCLC

Inclusion Criteria: * aged ≥18 years old; * histologically confirmed NSCLC; * 1-10 BMs on contrast-enhanced MRI; * stable extracranial disease status at the time of enrollment; * Eastern Cooperative Oncology Group (ECOG) performance status score of 0-2; * Normal function of organs and bone marrow within 14 days: Total bilirubin 1.5 times or less the upper limits of normal (ULN); AST and ALT 1.5 times or less the ULN; absolute neutrophil count≥ 500 cells/mm3; creatinine clearance rate(CCR) ≥45 mL/min; Platelet count≥50,000 cells/mm3; international normalized ratio(INR) ≤1.5，Prothrombin Time (PT)≤ 1.5 × ULN * Informed-consent Exclusion Criteria: * Intracranial metastases needed surgical decompression * Patients with contraindications for MRI * Previous radiotherapy or excision for intracranial metastases * The tumor has completely approached, encircled, or invaded the intravascular space of the great vessels (e.g., the pulmonary artery or the superior vena cava) * A cavity over 2cm in diameter of primary tumor or metastasis * Bleeding tendency or coagulation disorder * Hemoptysis (1/2 teaspoon blood/day) happened within 1 month * The use of full-dose anticoagulation within the past 1 month * Severe vascular disease occurred within 6 months * Gastrointestinal fistula, perforation or abdominal abscess occurred within 6 months * Hypertensive crisis, hypertensive encephalopathy, symptomatic heart failure (New York class II or above), active cerebrovascular disease or cardiovascu…