Summary
This clinical trial tests proton beam radiation therapy in patients after treatment for N2 non-small cell lung cancer that has been removed by surgery (resected). Proton therapy is a kind of radiation used to treat cancer. Like other types of radiation, proton therapy kills cancer cells and stops them from growing. Proton beam therapy is sometimes used after cancer surgery to reduce the risk of cancer recurrence (coming back). Giving proton beam radiation therapy may work better after surgery in patients with resected non-small cell lung cancer compared to conventional radiation treatment.