Hypofractionated Brain Radiation In EGFR Mutated Adenocarcinoma Cranial Disease (Hybrid)

Inclusion Criteria: * Histological or cytological confirmation of non-small cell lung cancer (NSCLC); * Diagnosis of brain metastases on a Gadolinium-enhanced MRI. * More than 3 sites of intracranial metastases, or the longest diameter of the intracranial lesion is more than 4 cm. * Positive EGFR mutation. * Life expectancy ≥3months. * Have one or more measurable encephalic lesions according to RECIST. * 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 or antibody to EGFR: gefitinib, erlotinib, herceptin, erbitux. * 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.