• 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;

• 5\. Measurable disease, as defined by RECIST v1.1 (tumor lesions long axis≥10mm, lymph nodes short axis ≥15mm);

• 6\. Life expectancy ≥3 months;

• 7\. Adequate pulmonary function;

• 8\. Adequate hematologic and end-organ function, defined by the following criteria:

‣ Hematology

• Hemoglobin (HGB) ≥90 g/L;

∙ Absolute neutrophil count (ANC) ≥ 1.5 x 10\^9/L;

∙ Platelet count (PLT) ≥ 100 x 10\^9/L;

∙ White blood cell count (WBC) ≥ 3.0 x 10\^9/L;

⁃ Serum chemistry

• Serum albumin (ALB) ≥ 30 g/L;

∙ Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) \< 3 x ULN;

∙ Total bilirubin (TBIL) ≤1.5 ULN; Note: Patients diagnosed with Gilbert's syndrome (persistent or recurrent hyperbilirubinemia \[mainly unconjugated bilirubin\] without evidence of hemolysis or liver pathology) after consultation with their physician can be allowed;

∙ Creatinine ≤ 1.5 ULN;

• 9\. Women of childbearing age must have taken reliable contraceptive measures or undergone a negative pregnancy test (serum or urine) within 7 days prior to enrollment. Both men and women of childbearing age must agree to maintain adequate contraceptive measures throughout the study and for 6 months following the completion of treatment;

• 10\. Patients must voluntarily participate in this study, sign the informed consent form, demonstrate good compliance, and actively cooperate with follow-up procedures.