The treatment of stage IIIA lung cancer is mainly based on surgery, and adjuvant treatments are selected according to the postoperative situation: if R0 is resected, postoperative chemotherapy (class 1) or sequential chemotherapy + radiotherapy (N2) is recommended; if R1 is resected, postoperative chemoradiation (sequential or synchronous) is recommended; if R2 is resected, synchronous radiotherapy is recommended. Progress of radiotherapy technology The development of radiotherapy technology has gone through conventional radiotherapy, conformal radiotherapy, IMRT/IGRT, and then MART, which is a process from ordinary radiotherapy to precise radiotherapy. With the passage of time and the emergence of new radiotherapy techniques, postoperative radiotherapy has become more and more important. There have been many Meta-analyses for stage IIIA since 1997, and the results have shown that postoperative radiotherapy improves patient status. The most recent study was conducted in 2015 and showed a 4.5% improvement in 5-year OS in N2-positive patients (34.8% vs 39.3%) and a 4.5-month prolongation of median survival (40.7 vs 45.2). Note 1 Postoperative radiotherapy indications are broadened and status is consolidated The Chinese Primary Lung Cancer Diagnostic and Treatment Guidelines 2015 Edition recommends that postoperative radiotherapy be applied to patients with insufficient surgical exploration or close surgical margins in addition to patients with positive postoperative margins; if postoperative pathology is negative for surgical margins but positive for mediastinal lymph nodes (pN2), the order of chemotherapy followed by sequential radiotherapy is recommended; for margin-positive pN2 stage tumors, simultaneous postoperative radiotherapy is recommended if the patient’s body permits. Although the status of postoperative radiotherapy is consolidated, the results of early PORT-Meta analysis were poor, and the analysis concluded that the reduction of survival rate by postoperative radiotherapy was related to the stage; it was obvious in stage I and II, and there was no significant effect of postoperative radiotherapy on survival rate in stage III cases. Since postoperative radiotherapy in stage III cases had no significant effect on survival, postoperative radiotherapy was not done earlier. There are flaws in this Meta-subdivision, including: the 3/9 randomized study is unpublished information; the sample size of each group is small; the time span is large; the staging is unclear; and the enrollment criteria varies widely. According to Prof. Yuan, the biggest problem of the study was the radiotherapy technique, as the majority of those used received Co60 irradiation, and some patients were irradiated with single-field irradiation. Note 2 Note special type stage IIIA (T3N2) Special type stage IIIA is divided into T3N2 (T ≥ 7cm) and T3N2 (invasion of chest wall): for T3N2 (T ≥ 7cm) patients, synchronous radiotherapy is preferred, or neoadjuvant chemotherapy ± radiotherapy, after which surgery ± chemotherapy ± radiotherapy if there is no progression, and radiotherapy ± chemotherapy if there is localized progression; for T3N2 (invasion of the chest wall) patients, cranial MRI or PET/CT was performed to confirm the absence of metastasis, followed by simultaneous radiotherapy. Note 3 Explore the value of surgery for subtype IIIA(N2) There is a well-known INT0139 study in this regard. The study included patients with stage III NSCLS, PS0-2, weight loss <5%, and total grasper case type iiia(n2-3) to explore the value of surgery. Results showed an improvement in pfs in patients with added surgery, p=0.017, but no significant difference in patient os. When paired analysis was performed, it was found that patients with lobectomy had significantly better os than radiotherapy alone, p=0.002, but patients with total lung resection instead had worse os than radiotherapy alone. chemotherapy, p=0.002, but the os of patients with total lung resection was instead inferior to radiotherapy alone. Based on the study, it can be concluded that in IIIA patients with clinical N2, after induction with simultaneous radiotherapy and chemotherapy, it is feasible to perform surgery or continue radiotherapy to a radical dose; the value of surgery is reflected in the lobectomy of those who can reach R0, and the prognosis for those who need to undergo total pneumonectomy is very poor, and it should be a contraindication.