A Study to Determine the Efficiency For Brain Metastasis NSCLC Patients Treated With Icotinib Alone or Combined With Radiation Therapy

Inclusion Criteria: * Histological or cytological confirmation of non-small-cell lung cancer (NSCLC) * Positive EGFR mutation（Ex19del or 21L858R） * Primary diagnosis of brain metastases * Have one or more measurable encephalic lesions according to RECIST * Extracranial transfer organ≤3 * ECGO:0-2 * Adequate hematological function: Absolute neutrophil count (ANC) ≥1.5 x 109/L, and Platelet count ≥100 x 109/L. * Adequate renal function: Serum creatinine ≤1.5 x ULN, or ≥ 50 ml/min. * Adequate liver function: Total bilirubin ≤ 1.5 x upper limit of normal (ULN) and -Alanine Aminotransferase (ALT) and Aspartate Aminotransferase (AST) \< 2.5 x ULN in the absence of liver metastases, or \< 5 x ULN in case of liver metastases. * Female subjects should not be pregnant. * All human subjects should able to comply with the required protocol and follow-up procedures, and able to receive oral medications. * Written informed consent provided. Exclusion Criteria: * Previous usage of EGFR-TKI : gefitinib, erlotinib, icotinib，or any other TKI * CSF or MRI findings consistent with metastases of spinal cord, meninges or meningeal. * Allergic to Icotinib. * Lack of physical integrity of the upper gastrointestinal tract, or malabsorption syndrome, or inability to take oral medication, or have active peptic ulcer disease. * Pregnancy or breast-feeding women. * Participate in the other anti-tumor clinical trials in 4 weeks. have quit from the trail before. * Any other serious underlying medical, psychological and other condition that, in the judgment of the investigator, may interfere with the planned staging, treatment and follow-up, affect patient compliance or place the patient at high risk from treatment-related complications.