At present, early-stage lung cancer has a chance to be cured by radiotherapy. Early stage lung cancer mainly refers to the situation where the lung lesions are relatively small and there are few or even no lymph node metastases. According to past experience, most lung cancers are not found in early stage, only 20%-30% of patients are found to be early stage lung cancers, and they are more often treated by surgery in the past with better results. However, patients who are old and frail and have more medical comorbidities and diabetic comorbidities are not conducive to surgery, so these patients are not allowed to undergo surgery. At present, with the advancement of radiotherapy equipment and technology, early radiotherapy also has advantages. Conventional radiotherapy has also been increased for the treatment of early lung cancer, but the irradiation area is relatively large, so the radiotherapy dose cannot be increased in order to protect normal organs. Studies have shown that the efficacy of radiotherapy can only reach about 50% of the effect of surgical treatment. However, now with the advancement of radiotherapy technology, we have introduced body stereotactic radiotherapy, which makes the target area more precise and protects the surrounding organs better, and makes technical preparation for the dose increase. After radiotherapy, treatment effects similar to surgery can be achieved, which is currently a good choice for treating early stage lung cancer. However, this technique is mainly for lung cancer without lymph node metastasis and <5cm in diameter, i.e. peripheral sites, and this radiotherapy can also be performed in central sites, and it is a more popular treatment method. In addition, if surgery or body x-ray is not possible for early stage lung cancer, radical radiotherapy can also be performed, but the side effects of radiotherapy may be greater than those of body x-ray radiotherapy. Currently, its efficacy is similar to that of surgery, with a survival rate of about 70%, which is better.