For small cell lung cancer with clinical stage Tl~2No I, lobectomy with hilar and mediastinal lymph node dissection is still recommended, followed by 4-6 courses of postoperative chemotherapy with EP regimen, and if positive hilar or (and) mediastinal lymph nodes are present, postoperative local radiotherapy is added. Less than 10% of stage I small cell lung cancers appear clinically, and the 5-year survival rate for surgery plus postoperative chemotherapy, is 35% to 40%, or 35% to 65% if preoperative chemotherapy is used. A retrospective study of 1260 cases of SCLC showed that the effect of surgery + radiotherapy + chemotherapy group was significantly better than other treatment groups, and the multifactorial analysis was statistically significant. For limited stage small cell lung cancer that is not suitable for surgery, combined radiotherapy and chemotherapy should be administered, and concurrent radiotherapy and chemotherapy can be considered if the patient’s general condition is better. If sequential radiotherapy and chemotherapy are used, radiotherapy should be started early after 1-2 courses of chemotherapy. The results of randomized trials have shown that the participation of early radiotherapy is better than those who receive radiotherapy after 4-6 courses of chemotherapy in terms of tumor local control rate, distant metastasis rate and patient survival rate. A Meta-analysis of 2103 cases showed that chemotherapy plus chest radiotherapy was associated with a 25%-30% reduction in local recurrence, a 14% reduction in mortality, and a 5%-7% increase in 2-year overall survival compared with chemotherapy alone. In the guidelines for the treatment of small cell lung cancer, radiotherapy is recommended by accelerated hyper-segmentation at 1.4-1.5 Gy/dose twice daily, with a total dose of 54 Gy (40 times. 28 days) or 45 Gy/(30 times. 21 days), respectively, and conventional irradiation at 2 Gy/dose once daily, with a total dose of no less than 54 Gy. The ECOG/RTOG study showed that radiotherapy given twice daily, compared with The ECOG/RTOG study showed that median survival time was 23 months versus 19 months with 2 daily radiotherapy sessions versus 1 daily radiotherapy session. EP regimens, the 1st line of treatment for small cell lung cancer, have an efficiency rate of 80%-100% and a complete remission rate of 50%-70%. EP regimens include etoposide (pedialyte glycoside) + cisplatin or etoposide decaplatin, and when used in combination with radiotherapy, etoposide decaplatin should be used because the latter has little mucosal toxicity, a low incidence of interstitial pneumonia, and when combined with radiation can reduce interstitial lung injury. Whether it is a stage I small cell lung cancer completely resected by surgery, or a small cell lung cancer in complete remission by combined radiotherapy or chemotherapy, preventive brain radiotherapy is generally recommended after 2 months. The dose is 24Gy/8 doses to 36Gy118 doses. Small cell lung cancer treatment guidelines, 1999 Meta-analysis, showed that prophylactic brain irradiation reduced the risk of death by 16% and increased the 3-year survival rate from 15% to 21% in small cell lung cancer in complete remission. However, after prophylactic brain radiotherapy, attention should still be paid to the psychiatric effects of the patient, and appropriate medication may be given if necessary. For patients who cannot achieve complete remission after combined radiotherapy and chemotherapy, 10%-15% of them may be of mixed type and can be considered for surgical resection if it is technically possible. In a study of a group of 28 cases, postoperative pathology revealed 36%, containing a non-small cell lung cancer component, with a median survival time of 24 months after surgery and a 5-year survival rate of 23%.