Lung cancer stage 3A belongs to the intermediate late stage, the overall cure rate of patients is relatively low, and the five-year survival rate of patients is around 30%. Although there is no distant metastasis of lung cancer stage 3A, the primary tumor of lung cancer is relatively large, and most of them have already had metastasis to peripheral lymph nodes, some patients can be given radical surgery, and then need to be assisted with chemotherapy or radiotherapy after surgery, and the overall cure rate of patients is not high. There are also some patients with stage 3A lung cancer, due to the wide spread of the tumor, it is not possible to radically resect the tumor lesion, and it is necessary to give neoadjuvant radiotherapy to shrink the tumor before operation, the cure rate of this part of the patients is even worse, and most of the patients can not be cured, and the survival period is obviously shortened.