Trial of ctDNA of Guidance to Determine PostOperative Radiation Therapy

Inclusion Criteria: 1. Have provided signed informed consent for the trial 2. Aged ≥18 years at the time of informed consent 3. Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 or 1 4. Diagnosed with histologically confirmed Stage II-III NSCLC and undergone surgical resection of lung tumor 5. No active second cancers/malignancy 6. Patients that received preoperative therapy (including chemotherapy and immunotherapy or others) are eligible 7. Willing and able to comply with all aspects of the protocol 8. Standard of care therapy and methods as per institution and investigator discretion - Exclusion Criteria: Exclusion Criteria 1. Discontinued treatment due to a Grade 3 or higher AEs with chemotherapy or immunotherapy or targeted therapy agent 2. With a history of another primary malignancy within the past 2 years that is considered an active malignancy by the enrolling physician. 3. Have known active CNS metastases and/or carcinomatous meningitis. 4. Have a history of (non-infectious) pneumonitis that required steroids or have current pneumonitis. 5. Have a history of interstitial lung disease. 6. Have a history or current evidence of any condition, therapy, or laboratory abnormality that might confound the results of the study, interfere with the participant's participation for the full duration of the study, or is not in the best interest of the participant to participate, in the opinion of the treating investigator. -