Omitting CTV for Locally Advanced NSCLC Responded to Immunotherapy and Chemotherapy

This trial tests whether radiation treatment for locally advanced non-small cell lung cancer (NSCLC) can be made safer — with less damage to healthy tissue — by targeting only the remaining visible tumor (not the original tumor area) after a good response to immunotherapy and chemotherapy. **You may be eligible if...** - You have confirmed Stage IIIA, IIIB, or IIIC non-small cell lung cancer - You cannot have surgery or have declined surgery after initial treatment - Your cancer showed response or stability after at least 2 cycles of combined immunotherapy and chemotherapy - Your overall health is good (performance status 0–1) with adequate organ function **You may NOT be eligible if...** - Your cancer progressed after initial treatment - Your tumor has EGFR, ALK, or ROS1 mutations - You have had previous chest radiation - You had significant immune-related side effects from prior immunotherapy - You are pregnant or breastfeeding - You have serious conditions like recent heart attack, severe arrhythmia, or active tuberculosis Talk to your doctor to see if this trial is right for you.