This study aims to explore the efficacy and safety of immunotherapy (PD-L1 inhibitor) maintenance following high-dose hyperfractionated simultaneous integrated boost radiotherapy concurrent chemotherapy in patients with limited-stage small cell lung cancer (LS-SCLC). This study is a prospective observational study. Additionally, liquid biopsy technology will be employed to identify biomarkers that can predict the efficacy of PD-L1 inhibitor after chemoradiotherapy in LS-SCLC.
1. Age 18-75 years, male or female;
2. Histologically or cytologically confirmed limited-stage small cell lung cancer (LS-SCLC) (AJCC, 8th edition);
3. No more than 2 cycles of chemotherapy or no previous systemic therapy;
4. ECOG PS 0-1;
1. Histological mixture of SCLC and NSCLC components;
2. Extensive-stage SCLC;
3. Patients with a history of allogeneic organ transplantation or allogeneic hematopoietic stem cell transplantation, or those planned for transplantation;
4. Treatment with immunosuppressive medications (including but not limited to prednisone, cyclophosphamide, azathioprine, methotrexate, thalidomide, and anti-tumor necrosis factor agents) within 14 days prior to the first dose of PD-L1 inhibitor, except for intranasal and inhaled corticosteroids or low-dose systemic steroids (i.e., ≤10 mg/day prednisolone or equivalent);