1.Basic examination items for staging (1) Clinical examination: physical examination. (2) Imaging examination: chest CT (contrast) + frontal and lateral chest films, brain MRI, abdominal ultrasound (liver, spleen, retroperitoneal lymph nodes, kidney, adrenal glands), bone isotope scan. (3) Laboratory: routine blood (RBC, Hb, WBC, PL), liver function (SGPT, blood bilirubin A/G, APK), renal function (uric acid, creatinine, urea nitrogen), glucose, electrolytes (Na+, Ca+, P++, K+), tumor markers: NSE. (4) Lung and heart: DLCO/FEV1 (absolute and relative values), EKG. (5) Fiberoptic bronchoscopy. (6) Pathology or cytology examination. (1) Limited stage: the tumor is confined to one side of the chest and can be included in one radiation field, including ipsilateral supraclavicular lymph node metastasis. (2) Extensive stage: the tumor is beyond the confined stage, including pathologically confirmed malignant pleural fluid, contralateral supraclavicular lymph node metastasis and distant metastasis. Pathological or cytological examination Biopsy or cytological examination by fiberoptic bronchoscopy. In the case of cytological examination, there must be two confirmed diagnoses of SCLC. 4.Diagnosis (1) Pathology or cytology to confirm the diagnosis. The diagnosis of cytology must be more than 2 times definite diagnosis of SCLC; (2) There is corresponding diagnostic evidence of imaging, relative to clinical symptoms and signs. 5.Physical condition evaluation KPS scoring criteria.