Indications for radiofrequency ablation treatment of lung cancer: (a) Best indications It means that the local tumor lesions can be completely inactivated by radiofrequency ablation treatment (the effect is similar to surgical resection). 1. Peripheral type lung cancer with maximum lesion diameter ≤5cm; 2. Number of lesions in one lung ≤3; 3. Clear boundary of the above lesions with paracancerous tissue of 0.5cm or more around, which can be used as “ablation margin”; 4. Primary tumor has been surgically resected or satisfactorily controlled, and the size and number of lesions are in accordance with Article 1 and 2 The local therapeutic effect of radiofrequency ablation is not related to the clinical type and pathological type. (2) Relative indications The scope of radiofrequency ablation cannot completely cover the whole lesion or cannot treat all lesions due to different reasons, and can only have the effect of reducing the tumor load or improving the symptoms. 1. Peripheral lung cancer with maximum diameter ≥ 5 cm; 2. The number of lesions in one lung ≥ 3; 3. Peripheral lung cancer or lung metastases with lesion size and number in accordance with the indications 1 and 2, but the lesions invade the heart, large blood vessels, trachea, esophagus, vertebrae and pleura, etc., and there is no “ablation margin”; 4. Central lung cancer 5.Pulmonary metastases whose primary lesions cannot be surgically resected or are unsatisfactorily controlled, and the size and number of lesions are in accordance with the indications 1 and 2.