IMRT Combined With Erlotinib for EGFR Wild Type Non-small Cell Lung Cancer With 4-10 Brain Metastases

Inclusion Criteria: * Pathologically confirmed NSCLC and wild type EGFR * 4-10 brain metastases on high quality CT scanning or MRI. * No previous EGFR-TKI treatment. * No previous brain radiotherapy. * More than 4 weeks from last chemotherapy. * Expected Survival of at least 2 months. * KPS≥ 70 * RTOG RPA performance status 0-1 * Lab tests should meet these criteria: White blood cell count ≥3×10\^9 /L;Platelet count≥100×10\^9 /L;Total bilirubin 1.5 times or less the upper limits of normal (ULN); AST and ALT 1.5 times or less the ULN; Serum creatinine 1.5 times or less the ULN or creatinine clearance rate(CCR) greater than or equal to 60 ml/min. * Pregnancy test (-) * Be able to sign informed consent form. Exclusion Criteria: * With unstable systematical diseases (concluding acute infection, grade 4 hypertension, unstable angina pectoris, congestive heart failure, hepatopathy, nephropathy, metabolic diseases) * With metastases on meninges. * Taking antiepileptics (phenytoin sodium etc.) at the same time * Unable to oral medication. * Previous or recent another malignancy, except for nonmelanoma skin cancer or cervical cancer in situ