Primary Tumor Radiotherapy Omitting CTV for Patients With Advanced NSCLC Responded to Immunotherapy and Chemotherapy

Inclusion Criteria: 1. Histologically or cytologically confirmed advanced non-small cell lung cancer (according to the 8th edition of the TNM cancer staging system of AJCC and UICC); 2. After over two cycles of chemotherapy combined with immunotherapy, the efficacy was CR, PR or SD (with a decreasing trend); 3. Age 18 to 80 years old, performance status 0-1; 4. measurable or evaluable lesions; 5. Survival expectancy is not less than 6 months; 6. adequate cardiac, pulmonary, renal, and hepatic and bone marrow function Exclusion Criteria: 1. tumor progress after therapy with immunotherapy and chemotherapy 2. EGFR, ALK, or ROS1 mutation; 3. Previous thoracic radiotherapy; 4. grade 2 or more immune-related adverse events after induction immunotherapy 5. Previous malignancies (except stage I non-melanic skin cancer or cervical carcinoma in situ); 6. Pregnant or lactating women 7. undergoing other clinical trials; 8. Have serious comorbidities, including myocardial infarction, severe arrhythmia, severe cerebrovascular disease, ulcer disease, psychosis and uncontrollable diabetes; 9. Patients with HIV positive and undergoing antiviral therapy; 10. Active tuberculosis