Durvalumab Combined With Chemotherapy and Stereotactic Body Radiotherapy (SBRT) in Patients With Oligometastatic Non-small Cell Lung Cancer (NSCLC)

Inclusion Criteria: * Histologically confirmed non-small cell lung cancer * ≤3 metastatic organs and ≤5 metastatic lesions (supraclavicular and mediastinal lymph nodes are not classified as distant metastasis; other lymph node * metastasis一group lymph node region will be classified as one metastatic lesion） * Tissue biopsy prior to treatment * ECOG performance score 0-1 Exclusion Criteria: * EGFR mutation or ALK positive. * Evidence on pulmonary interstitial disease or symptoms of active non-infectious pneumonia. * Active infection including tuberculosis, hepatitis B, hepatitis C, or human immunodeficiency virus. * Previous treatment with antibody against pd -1, pd - L1, pd - L2, CD137 or CTLA-4 (including ipilimumab or any antibody or drug against T cell co-stimulation or checkpoint pathway).