Phase II Trial of SBRT Compared With Conventional Radiotherapy for Oligometastatic Non-Small Cell Lung Cancer

Inclusion Criteria: * Histologically proven non-small-cell lung cancer. * Stage IV oligometastatic NSCLC according to UICC stage system(version 7,2009) or oligometastatic disease after radical operation for stage I-III NSCLC. * The patients receive firstly 4-6 cycles chemotherapy (platinum-based doublet chemotherapy), and achieve response(stable disease or partial response or complete response). * Staging with chest CT scan, abdominal ultrasonography , MRI brain, Bone scan and/or FDG PET-CT whole body scan. * Number of metastatic lesions equal to or less than 5. * Maximum diameter of metastatic tumors equal to or less than 5cm. * ECOG performance status 0-2 at time of registration. * EGFR testing is mandatory. * No brain metastasis in MRI. * No liver metastasis in abdominal CT or MRI. * No malignant pleural effusion or pericardial effusion or peritoneal effusion. * Acceptable lung function for radical lung radiotherapy. * Stable lab values: Hematological: Absolute neutrophil count (ANC) ≥1.5×109/L, Platelets ≥100×109/L, Hemoglobin≥9 g/dL Renal: Creatinine OR Measured or calculated creatinine clearance (CrCl)(glomerular filtration rate \[GFR\] can also be used in place of creatinine or CrCl) ≤1.5×the upper limit of normal (ULN) OR ≥60 mL/min for patient with creatinine levels\>1.5× institutional ULN Hepatic: Total bilirubin ≤1.5×ULN OR Direct bilirubin ≤ULN for patients with total bilirubin levels \>1.5×ULN, Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≤2.5×ULN,globulin≥20 g/L, albumin≥30 g/L. * No relevant co-morbidities, including pulmonary fibrosis and connective tissue disorders * Able to understand and give written informed consent and comply with study procedures. Exclusion Criteria: * Patient has had palliative radiotherapy to any tumour site prior to registration and/or requires palliative radiotherapy prior to randomisation. * Patient has received any molecular targeted therapeutic drugs for NSCLC malignancy. * The patients receive firstly 4-6 cycles chemotherapy (platinum-based doublet chemotherapy), and achieve progressive disease. * Any unstable systemic disease, including active infection, uncontrolled high blood pressure, unstable angina, newly observed angina pectoris within the past 3 months, congestive heart failure (New York heart association (NYHA) class II or higher), myocardial infarction onset six months before included into the group, and severe arrhythmia, liver, kidney, or metabolic disease in need of drug therapy. * Previously diagnosed with immunodeficiency disease. * Human immunodeficiency virus (HIV) infection. * Women in pregnancy or lactation. * Patients with mental illness, considered as "can't fully understand the issues of this research". * other Cancer history. * Histologically confirmed small cell carcinoma or other non NSCLC compositions in the cancer tissue. * Brain metastasis or liver metastasis or malignant pleural effusion or pericardial effusion or peritoneal effusion.