Radiation Therapy in Patients With Limited-Stage Small Cell Lung Cancer in Complete Remission

RATIONALE: Radiation therapy uses high-energy x-rays to kill tumor cells and prevent the spread of cancer to the brain. It is not yet known if standard-dose radiation therapy is more effective than high-dose radiation therapy in preventing the spread of limited-stage small cell lung cancer cells to the brain. PURPOSE: This randomized phase III trial is comparing two different regimens of radiation therapy to see how well they work in treating patients with limited-stage small cell lung cancer in complete remission.