Clinical Research Directory

Inclusion Criteria: * Age ≥ 18 years; * Pathologically or cytologically confirmed primary non-small cell lung cancer (NSCLC) with a clinical stage of III (according to the 8th edition or latest version of the AJCC staging system); * Eligible for radical radiotherapy or chemoradiotherapy to the chest, with a planned total dose of ≥50 Gy to the chest, using a fractionation schedule of 1.8-2.0 Gy per fraction (conventional fractionation) or a high-dose fractionation regimen permitted by the protocol; * Planned to undergo periodic blood tests before and after radiotherapy, including absolute lymphocyte count; * ECOG performance status of 0-2; * Able to undergo regular follow-up and provide blood samples and imaging evaluations as required by the protocol. Exclusion Criteria: * Previous history of thoracic or whole-body radiation therapy; * A diagnosis of radiation-induced lymphocytopenia or baseline lymphocytopenia graded ≥ Grade 2 (according to the CTCAE criteria) prior to study enrollment; * Patients with a history of or known primary immunodeficiency, active autoimmune disease, long-term systemic glucocorticoid therapy (prednisone-equivalent dose \> 10 mg/day), or long-term use of immunosuppressants following organ transplantation; * History of concurrent malignancy (excluding basal cell carcinoma of the skin or cervical carcinoma in situ that has been treated curatively and has been recurrence-free for at least 5 years); * Pregnant or lactating women; * Any other condition deemed by the investigator to render the subject unsuitable for participation in this clinical study, including severe hepatic, renal, hematologic, or other organ dysfunction; * Irreversible contraindications to the radiotherapy plan or dose delivery.