Radiofrequency ablation is a new technique for effective treatment of primary and metastatic lung cancer that has become prevalent in recent years. This method has a good clinical application prospect because of its precise efficacy (with potential to achieve similar effect as surgical resection), mild trauma, fast recovery, high quality of life, and repeatability. Like the principle of radiofrequency ablation of liver cancer, radiofrequency ablation of lung cancer also causes coagulative necrosis of tumor tissues through the principle of high heat, thus completely losing its activity and metastatic potential. At present, there are various types of electrode needles used for lung cancer ablation, the more commonly used ones are mainly “Christmas tree-like” or “umbrella” electrodes, and the latter are more in line with the morphological characteristics of tumors and more safe and controllable. Indications for radiofrequency ablation of lung cancer 1.Patients who cannot tolerate surgery because of heart and other important organ insufficiency, or those with normal organ function and refuse surgery for middle or late stage primary or metastatic lung cancer. 2.There is no uniform standard for the diameter of single tumor, in principle, it should not be >5cm. Otherwise, it may need to be performed in stages. There is no uniform standard for the number of tumors to be ablated at one time, which can be determined according to the patient’s general and lung conditions and the size of the tumor. The number of tumors to be ablated at one time should preferably be less than 6 for those within 2 cm, and the number should be reduced for those with larger lung cancer. In order to prevent metastasis of tumor in patients who are not sensitive to radiotherapy or chemotherapy, it is recommended for eligible patients with primary lung cancer to eliminate visible tumor by radiofrequency ablation first, and then cooperate with radiotherapy and chemotherapy to avoid losing the chance of cure. 6.Metastatic lung cancer can decide whether to combine radiofrequency ablation with radiotherapy according to the primary tumor site and biological traits 7.Liver tumor is not sensitive to the existing chemotherapy drugs, so it is recommended to directly ablate radiofrequency or combine with radiotherapy for lung metastasis of liver cancer 8.Lung metastasis after liver transplantation 2.Contraindications 1.Severe failure of important organ functions (heart, organs, lungs and kidneys); 2.Lung hilar lesions with large cavities 3.Central Lung cancer combined with severe obstructive pneumonia 4.Lung cancer metastasis to the cervical and thoracic vertebrae, with serious damage to the vertebral body and risk of paraplegia 5.Diffuse metastatic lesions in the lungs or extensive metastases in both lungs 6.Extensive metastases in other important organs other than the lungs 3.Complications The complications of radiofrequency ablation treatment for lung cancer are not high, but patients will have postoperative symptoms such as “post-radiofrequency flu-like syndrome (fever, poor performance, weakness, etc.)”. This is a normal symptom, which usually disappears in a week or so, but the recovery time of individual patients is relatively longer. The more serious complications that require special treatment are generally around 3-5%, and even life-threatening in extreme cases cannot be excluded. Mainly include: 1, pneumothorax: mostly due to electrode needle puncture, more likely to occur in advanced age, emphysema, can occur in the intraoperative or postoperative. A small amount of gas can be absorbed on its own without disposal, and more serious pneumothorax with obvious dyspnea and other symptoms can be lifted by thoracic suction or closed drainage of the chest cavity. 2, pleural effusion: mostly related to pleural irritation. Small to medium amount of pleural effusion can be absorbed on its own without obvious symptoms. If the effusion is serious, symptoms such as respiratory distress can be relieved by thoracentesis drainage. Hemothorax may also occur in a small number of patients, which is related to bleeding from the puncture needle tract, and can be controlled by conservative treatment in general, and very few need to stop bleeding through thoracoscopy or embolization treatment, and those who are ineffective may need open-heart surgery to stop bleeding. Hemoptysis: mostly occurs in patients with central type lung cancer, the mass is often wrapped or adhered to bronchus and large blood vessels, which may damage the blood vessels and cause hemoptysis during puncture. 4. Pericardial effusion: heat stimulation of pericardium may cause pericardial effusion, which should be treated by pericardial puncture as soon as possible if symptoms are obvious. 5.Pulmonary infection: If the patient has long-standing chronic obstructive pulmonary disease, pulmonary infection or ablation foci infection may occur after ablation, antibiotics may be applied prophylactically before surgery or anti-infection treatment may be given after surgery. Evaluation of efficacy: There is no standard way to evaluate the efficacy at home and abroad, and many scholars only evaluate the tumor shrinkage rate, which is not scientific enough. The complete necrosis rate, recurrence rate and survival rate of tumor after radiofrequency should be used as the efficacy evaluation index. Marcallo et al. treated 54 cases of 64 lung tumors by radiofrequency ablation, including 40 cases of primary non-small cell lung cancer and 24 cases of pulmonary metastases with a mean diameter of 2.4 cm. The CT follow-up results showed that the overall treatment efficiency was 61.9%, including 70.8% for pulmonary metastases and 69.7% for tumors less than 3 cm in diameter. The average survival time was 17.3 months and the average tumor-free period was 12.9 months. Zhao Hengjun et al. reported 60 cases of lung cancer treated by radiofrequency ablation, 55 cases (91.7%) had shrunken masses after treatment, 1 case had bone metastasis, 2 cases had recurrence in situ, and 2 cases had intrapulmonary metastasis after surgery. The efficiency of peripheral lung cancer was 97.9% (47/48), and that of central lung cancer was 33.3% (4/12). Zhao Jian et al. reported 42 cases in the radiofrequency ablation combined with radiotherapy treatment group and 38 cases in the conventional radiotherapy treatment group. The results showed that the KPS improvement rate was 25.87% and 10.52%, the stabilization rate was 42.86% and 36.84%, and the deterioration rate was 28.57% and 58.63% in the combined group and the conventional group, respectively; the KPS score in the combined group was better than that in the conventional group. The local recurrence rate of primary foci was significantly lower in the comprehensive group (28.57%) than in the conventional group (50.00%); the median survival was 16 months in the comprehensive group and 14 months in the conventional group; the survival rates at 1, 2 and 3 years were slightly higher in the comprehensive group (63.53%, 31.99% and 21.33%) than in the conventional group (53.50%, 29.13% and 16.18%). Radiofrequency ablation treatment for lung cancer has precise efficacy, high safety and quick recovery. Compared with surgical resection, the damage is milder, the effect of good site and appropriate size is not significantly different from that of surgical resection, and multiple pieces can be eliminated at one time. Compared with thoracoscopic lung tumor resection, it has a wider application. Compared with radiation therapy, the treatment time is shorter, there are no complications such as systemic immune function decline and bone marrow suppression after radiotherapy, and the cost is only about half of radiotherapy. Therefore, radiofrequency ablation is undoubtedly one of the first choice curative methods for lung tumors, and its reasonable combination with surgical resection, radiotherapy and chemotherapy will greatly increase the tumor control rate, improve the quality of life, and prolong the survival of patients.