The goal of this clinical trial is to learn if using an incentive spirometer can reduce lung problems in people with advanced lung cancer who are receiving chemotherapy and radiation therapy. The main questions the study aims to answer are: Does using an incentive spirometer lower the chances of developing lung inflammation (pneumonitis)? Does it improve overall survival and quality of life? Participants will: Use an incentive spirometer, a device that helps with deep breathing, 10 times every hour while awake. Continue using the spirometer daily during treatment and for up to three months after treatment. Complete quality of life assessments at the start of the study and at 3, 6, and 12 months. Researchers will compare the results to see if the incentive spirometer helps reduce lung problems and improves participants\' well-being during and after their cancer treatment.