There are benign and malignant tumors of the liver. Benign tumors of the liver are uncommon. Malignant tumors of the liver are mainly primary and secondary hepatocellular carcinoma. Other malignant tumors such as hepatic sarcoma and malignant hemangioendothelial cell tumor are rare. In clinical practice, liver tumors are usually treated with a combination of surgery, radiotherapy and traditional Chinese medicine in western medicine, but the cure rate of late stage patients is low due to the spread of tumor cells, so it is necessary to achieve early detection, early diagnosis and early treatment of liver tumors. The treatment methods of liver tumor currently include: surgical resection, hepatic artery vascular embolization, alcohol injection method, cryotherapy, radiofrequency ablation and so on. I. What is radiofrequency ablation? Radiofrequency is a kind of high frequency vibration with a frequency of 150,000 times per second. Under the action of high frequency alternating current, the direction of concentration change of ions changes with the direction of current for positive and negative half-cycle round trip. Under the high frequency oscillation, the ions between the two electrodes move rapidly along the direction of power line and gradually change from moving state to vibrating state. Due to the poor heat dissipation of tumor, the temperature of tumor tissue is higher than its neighboring normal tissue, coupled with the sensitivity of cancer cells to high heat, high heat can kill cancer cells without side effects. Who can undergo radiofrequency ablation? 1.The diameter of single tumor lesion≦5cm, the diameter of multiple tumor lesions≦3 cancer lesions, the diameter of the largest tumor lesion≦3cm; 2.Tumor recurrence after surgical resection, tumor size characteristics with the above requirements; 3.Tumor boundary is clear, there is enough safety range for tumor extinction; 4.No extrahepatic metastasis. Who must not undergo radiofrequency ablation? 1.Patients with extrahepatic metastasis of liver cancer; 2.Patients with severe cardiopulmonary and cerebral diseases who cannot tolerate radiofrequency treatment; 3.Patients with severe liver insufficiency, liver function Child C level; 4.Patients with severe coagulation disorder. RF ablation process 1.Anesthesia: can be performed under intravenous anesthesia or local anesthesia combined with intravenous anesthesia, sedative and analgesic drugs can be added when using local anesthesia; 2.Guidance: guided by ultrasound, when the tumor is located at the top of the diaphragm with pulmonary air deflection. When the tumor is located at the top of the diaphragm with lung gas flexure, it can be guided by CT positioning; 3. Ablation route: there are three kinds of ablation: percutaneous, laparoscopic and open; 4. Ablation scope: after puncture and placement of RF electrode, the ablation process should be completed according to the instructions of RF transmitter. The ablation scope must completely cover the tumor scope and exceed its border by 0.5-1cm. V. Common problems after RF ablation The changes of vital signs and abdominal condition should be closely monitored to prevent complications; bleeding and biliary fistula are more serious complications, but the incidence is low; local swelling and pain or fever are more common after ablation, which usually only need symptomatic treatment. After the operation, ultrasound or enhanced CT is performed regularly, and changes in AFP, blood routine and liver and kidney function are checked to evaluate the efficacy and decide whether additional treatment is needed.