The ctDNA for Evaluating Whether to Use Adjuvant Therapy After SBRT in Patients With Early Lung Cancer

Inclusion Criteria: 1. Patients pathologically diagnosed as non-small cell lung cancer, and was early stage（AJCC 8th）; 2. Patients aged between 18 -80 years; with expected survival time\>3 months. 3. Patients with normal organ function within 30 days prior to treatment, the following criteria are met: 1. blood routine examination criteria : i) hemoglobin (HB) ≥90g/L; ii) absolute neutrophil count (ANC) ≥1.5×10e9/L; iii) platelet (PLT) ≥80×10e9/L; b) biochemical tests meet the following criteria: i) total bilirubin (TBIL) ≤1.5 times of upper limit of normal (ULN); ii) alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤2.5 ULN; iii) serum creatinine (Cr) ≤1.5 ULN or creatinine clearance (CCr) ≥60mL/min; Exclusion Criteria: 1. Patients with small cell lung cancer (including small cell carcinoma and non-small cell carcinoma mixed lung cancer); 2. Patients with factors that affect oral medication (such as cannot swallow, chronic diarrhea and intestinal obstruction, etc.) or intravenous medication; 3. Patients with any other severe and/or uncontrolled disease; 4. Patients with a history of psychotropic medicine abuse and cannot quit or have mental disorders; 5. Patients with disease which will severely endanger their security and could not complete this study, according to the judgement of researchers；