Summary
This phase II/III trial compares the effect of adding radiation therapy to the usual maintenance therapy with atezolizumab versus atezolizumab alone in patients who have already received atezolizumab plus chemotherapy for the treatment of small cell lung cancer that has spread outside of the lung or to other parts of the body (extensive stage). Immunotherapy with monoclonal antibodies, such as atezolizumab, may help the body's immune system attack the cancer, and may interfere with the ability of tumor cells to grow and spread. Radiation therapy uses high energy x-rays to kill tumor cells and shrink tumors. Giving radiation therapy in addition to atezolizumab may extend the time without extensive small cell lung cancer growing or spreading compared to atezolizumab alone.