The purpose of this study is to evaluate the efficacy of icotinib alone or in combination with radiation therapy for NSCLC patients harboring EGFR mutation with brain metastases. The primary endpoint is overall survival .

Non-small cell lung cancer (NSCLC) is one of the malignant tumors with the highest incidence of brain metastases, and most patients died due to the progression of brain metastases. Some research show that icotinib combined with radiation therapy can improve the efficiency of NSCLC with brain metastases, but there is still controversial about the timing of radiation therapy intervention . This study is a prospective, multi-center, randomized, controlled trial of icotinib combined with early intervention or late intervention radiation therapy for NSCLC patients harboring EGFR mutation with brain metastases. They will be treated with icotinib and divided into 2 groups. Group 1: the radiation therapy will start within 1 month after icotinib treatment; Group2: the patients will be treated with icotinib first, radiation therapy intervene if disease progress.

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.