This study is a randomized phase III trial that aiming to investigate the role of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) guided hypofractionated radiotherapy (hypo-RT) in patients with locally advanced non-small cell lung cancer (LA-NSCLC) who are planned to receive hypo-RT combined with concurrent chemotherapy and consolidative immunotherapy. Patients will be randomized in a 1:1 ratio into two groups:

1. The study group will undergo adaptive dose-painting hypo-RT based on DCE-MRI.
2. The control group will undergo hypo-RT based on enhanced CT.

The treatment-related toxicity, local control and long-term survival will be evaluated compared between MRI-guided and CT-guided hypo-RT.

Inclusion Criteria:

• Male or female aged between 18 and 75 years old.
• Patients must have histological or cytological confirmation of locally advanced, unresectable (stage III) non-small cell lung cancer (NSCLC).
• No prior radiation therapy or surgery.
• Expected life expectancy of at least 12 weeks.
• World Health Organization (WHO) performance status score of 0 or 1.
• Able to undergo magnetic resonance imaging (MRI) examination.
• Organ and bone marrow function meeting the following criteria: Forced expiratory volume in 1 second (FEV1) ≥ 800 ml; Absolute neutrophil count ≥ 1.5 × 10^9/L; Platelets ≥ 100 × 10^9/L; Hemoglobin ≥ 9.0 g/dL; Serum creatinine clearance rate calculated by the Cockcroft-Gault formula ≥ 50 mL/min (Cockcroft and Gault 1976); Serum bilirubin ≤ 1.5 times the upper limit of normal (ULN); Aspartate transaminase (AST) and alanine transaminase (ALT) ≤ 2.5 times ULN.

Exclusion Criteria:

• Contraindications to MRI examination.
• Concurrent participation in another clinical study, unless it is an observational (non-interventional) clinical study.
• Histological type of mixed small cell and non-small cell lung cancer.
• The presence of sensitive EGFR mutations or ALK rearrangements.
• Major surgery performed within 4 weeks prior to entering the study (excluding vascular access).
• History or occurrence of autoimmune disease within the past 2 years.
• Active or history of inflammatory bowel disease (e.g., Crohn's disease, ulcerative colitis).
• History of primary immunodeficiency.
• History of organ transplantation requiring immunosuppressive therapy.
• Average QT interval (QTc) ≥ 470 ms calculated from 3 ECG cycles using Bazett's correction.
• Uncontrolled comorbidities, including but not limited to persistent or active infection, symptomatic congestive heart failure, poorly controlled hypertension, unstable angina, arrhythmia, active peptic ulcer disease or gastritis, active bleeding disorder, human immunodeficiency virus (HIV), or psychiatric/social situations that would limit compliance with study requirements or impair the ability to provide written informed consent.
• Active tuberculosis.
• Receipt of a live attenuated vaccine within 30 days prior to the start of the study.
• History of another primary malignancy within 5 years, excluding adequately treated basal or squamous cell skin cancer or in situ cervical cancer.
• Pregnant or breastfeeding women; or males and females of reproductive potential not using effective contraception.