Assessment of Adebelizumab Combined with Chemotherapy in Concurrent Radiotherapy Versus Sequential Radiotherapy As First-Line Treatment for Extensive-Stage Small Cell Lung Cancer

"Cohort 1:~Induction Phase: Patients will receive three cycles of atezolizumab in combination with carboplatin/cisplatin plus etoposide.~Concurrent Radiotherapy Phase: the fourth cycle will incorporate concurrent radiotherapy along with atezolizumab and chemotherapy.~Maintenance Phase: Atezolizumab monotherapy will be administered until disease progression or intolerance by the patient, with atezolizumab being administered for a maximum duration of 2 years.~Cohort 2:~Induction Phase: Patients will receive three cycles of atezolizumab in combination with carboplatin/cisplatin plus etoposide.~Sequential Radiotherapy Phase: the fourth cycle will receive sequential radiotherapy in combination with atezolizumab.Final，Atezolizumab monotherapy will be continued until disease progression."