Liver cancer is known as “King of Cancer” and is one of the most common malignant tumors in clinical practice. The global incidence rate is increasing year by year and has exceeded 626,000/year, ranking 5th among malignant tumors; death is close to 600,000/year, ranking 3rd among tumor-related deaths. Liver cancer is highly prevalent in China, and currently, the number of incidences in China accounts for about 55% of the global incidence; it ranks second after lung cancer in tumor-related deaths. The number of deaths due to liver cancer exceeds 100,000 each year. The surgical resection rate of middle and late stage liver cancer is only about 5%-10%, and the surgical mortality rate is over 10%. With the rapid development of imaging technology, tumor treatment has entered the minimally invasive era. Commonly used local ablation techniques: radiofrequency ablation, microwave ablation, laser ablation, cryoablation, chemical ablation (ethanol, acetic acid-Ethanolablation) and ultrasound ablation. I. What are the principles and characteristics of microwave ablation for liver cancer treatment? Under the precise guidance of CT, microwave ablation needle is used to puncture into the liver tumor for direct ablation treatment. The thermal effect of microwave needle is actually using the same principle of microwave oven to make liver cancer tissues reach a temperature of over 100℃ in a few minutes, causing coagulative necrosis of tumor target tissues with little or no damage to surrounding tissues, thus achieving the purpose of “burning” the tumor cells. The most important feature of this minimally invasive treatment is that it is less invasive and has less impact on the patient’s whole body. Microwave ablation treatment not only has no side effects caused by radiotherapy and chemotherapy, such as hair loss, weakness, anorexia, and decrease of white blood cells, but also has the effect of increasing the immunity of the body. Curing liver cancer without surgery has become a reality. Which liver cancer patients are suitable for microwave ablation treatment? 1.Single lesion ≤5cm; 2.Multiple lesions less than 3 and the largest lesion diameter ≤4cm; 3.No portal vein cancer thrombus or extrahepatic metastasis. What are the contraindications of microwave ablation treatment? 1.Where the ultrasound channel (puncture path) is unclear and ambiguous. 2.Severe impairment of liver function, large amount of ascites; severe impairment of kidney function; severe cardiac insufficiency. 3, Those with fever caused by infection and too poor general condition. 4.Abnormal mechanism of coagulation system and bleeding tendency. 4.What are the advantages of microwave ablation for liver cancer treatment? 1.Minimally invasive, the treatment only uses “needle” (microwave antenna or microwave “tip” – 2mm in diameter) to enter the tumor precisely under ultrasonic guidance, and the skin only has a needle eye of less than 3mm, so there is no scar and no suture, which avoids the damage of major surgery to the whole body. “It avoids the harm of major surgery to the whole body. 2.Short treatment time and high efficacy. Tumors with single lesion ≤5cm can be inactivated at one time under local anesthesia or general anesthesia, and one treatment time only takes about 15 minutes. Conformal ablation can be performed, which is based on the shape of the tumor, which can improve the efficacy and reduce recurrence. 4.Wide indications, for liver cancer that cannot be resected surgically, invalidated by vascular embolization or with poor liver function, ultrasonic intervention can still be used for treatment, which can achieve tumor reduction, palliative treatment, alleviate pain, prolong life and improve life quality. 5.It can be widely combined with other treatments, such as transhepatic artery embolization chemotherapy (TACE) will help to strengthen the effective control of microwave ablation tumor and expand its indications. 6.It can be repeatedly treated for many times. 7.The cost is cheap, compared with the cost of surgery, only less than one-third of the former. V. What is the advantage of microwave ablation compared with radiofrequency ablation? 1.Microwave ablation (MWA) is an active ablation, while RF ablation is a passive ablation. In the living body, the conduction of microwave does not depend on the electrical conductivity of the tissue, and is less affected by tissue charring and dehydration, so the ablation range of microwave ablation is larger, and the temperature inside the tumor is high enough for shorter ablation time and more complete tumor inactivation. 2.Compared with radiofrequency ablation, microwave ablation is less affected by the cooling effect caused by blood perfusion, and can achieve uniform inactivation for tumor target areas near blood vessels. 3.Multiple microwave energy sources can be applied at the same time, so that there will be no mutual interference in the process of RF ablation, thus achieving a larger ablation range in a short period of time. 4.The price of the same microwave needle is about 4000 yuan lower than that of RF needle. What is the efficacy of microwave ablation in treating liver cancer? At present, microwave ablation therapy is rapidly emerging all over the world, and tens of thousands of patients with liver cancer have been reported to have achieved therapeutic efficacy comparable to that of surgery. A group of domestic reports: 288 liver cancer patients with 477 tumors underwent microwave ablation therapy. The cumulative survival rate of patients from 1 to 5 years reached 93%, 82%, 72%, 63% and 51%, respectively, among which the long-term survival rate of patients with tumor diameter <4cm and cirrhosis ChildA grade was higher, and the local recurrence of tumor only accounted for 8%. What are the complications and side effects of microwave ablation? The complications of microwave ablation are similar to those of radiofrequency ablation. The side effects include mild pain, post-ablation syndrome and asymptomatic pleural effusion. The post-ablation syndrome is often characterized by low-grade fever and general malaise, the duration of which is related to the volume of tissue necrosis caused by microwave ablation and the patient's general condition, and usually lasts about 3 days. These side effects are often self-limiting and usually do not require treatment. Serious complications include bile duct stricture, bleeding, liver abscess, skin burns, tumor implantation, etc., but the incidence is low. What is the development of microwave ablation of tumor at home and abroad? At present, the United States, the United Kingdom and other countries have carried out clinical research on tumor microwave ablation treatment; microwave ablation treatment compared with radiofrequency ablation treatment: 1, less painful; 2, shorter time; 3, lower cost.