GCC 2546- Motion Management

Inclusion Criteria: 1. Adult (≥18 years) patients (both sexes) with histologically diagnosed Stage II-IIIb NSCLC 2. Patients to be treated with definitive external beam photon radiotherapy with or without systemic therapy (e.g., chemotherapy, immunotherapy). 3. No restrictions on number radiotherapy fractions, or location/number of lesions 4. ECOG performance status ≤ 3 5. Ability to undergo MRI scans 6. Patient has signed informed consent document and agreed to study procedures Exclusion Criteria: 1. Pre-existing contraindications for MRI, such as any MRI-conditional or MRI-unsafe foreign objects within the body, non-removable ear cochlear or eye implant, aneurysm clip, cardiac pacemaker/wires, internal defibrillator, tissue expander, recent stent placement, penile prosthesis, medication patch, artificial limb, pregnancy, and claustrophobia 2. Women who are pregnant or trying to get pregnant (self-reported) 3. Pain in supine position or inability to raise arm above head in supine position