High Dose Icotinib With Sequential SRS For NSCLC Patients Harboring EGFR Mutation With Brain Metastases

Inclusion Criteria:

* Histological or cytological confirmation of non-small cell lung cancer (NSCLC);
* Diagnosis of brain metastases on a Gadolinium-enhanced MRI.
* Less than 10 sites of intracranial metastases, or the longest diameter of the intracranial lesion is less than 4cm.
* Positive EGFR mutation（Ex19del or 21L858R）.
* Life expectancy ≥3months.
* Have one or more measurable encephalic lesions according to RECIST.
* The patient has not received radiotherapy for the head or extracranial target lesions before.
* 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.
* 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.