Exploration on the Value of MRD Based on ctDNA Detection in Predicting Recurrence of Resected Non-small Cell Lung Cancer

Inclusion Criteria: 1. Age ≥ 18 years old, regardless of gender; 2. Patients with pathological diagnosis of non-small cell lung cancer and clinical staging of stage IB-IIIB; 3. Able to undergo radical surgical treatment; 4. Physical condition score (ECOG) ≤1; 5. The expected survival time exceeds 24 months; 6. Volunteer to participate in this study and sign an informed consent form. Exclusion Criteria: 1. Individuals with a history of other malignant tumors within 5 years; 2. Those who have undergone neoadjuvant therapy before surgery; 3. Postoperative incision margin R1 or incision margin R2; 4. Those who have undergone a blood transfusion within 2 weeks before the surgery; 5. Individuals with systemic inflammatory response syndrome; 6. Those with serious diseases of important organs such as the heart, lungs, kidneys, and brain; 7. Participants in other clinical trials within the past 30 days and have taken investigational drugs; 8. Due to various reasons, sampling cannot be completed, samples do not meet the requirements, or baseline samples (preoperative and postoperative plasma samples, tumor tissue samples) are incomplete; 9. Researchers believe that it is not appropriate to participate in this experiment.