1.What is local ablation therapy? Local ablation therapy is a type of treatment that directly kills tumor tissues by physical or chemical methods with the guidance of medical imaging technology to target and locate the tumor. It mainly includes radiofrequency ablation (RFA), microwave ablation (MWA), cryoablation, high power focused ultrasound ablation (HIFU) and anhydrous ethanol injection (PEI), which are minimally invasive, safe, simple and easy to perform multiple times. Duan Binwei, Department of Hepatobiliary Surgery, Beijing Youan Hospital, Capital Medical University, and image guided techniques include US, CT and MRI, while the treatment routes are percutaneous, trans-laparoscopic surgery and open surgery. 2.Which tumors are suitable for local ablation treatment? Not all hepatocellular carcinomas are suitable for local ablation therapy, and only by strictly mastering the indications can patients get the maximum benefit. (1) For liver cancer with tumor ≤3cm, the effect is basically the same as that of hepatectomy and liver transplantation, which can basically achieve clinical cure. (2) For a single tumor larger than 3cm and ≤5cm; or a number of tumors ≤3 and the largest diameter ≤3cm. which are not suitable for surgical resection or cannot undergo liver transplantation, local ablation therapy can be performed. (3) No invasion of blood vessels, bile ducts and adjacent organs as well as distant metastasis. The liver function is graded as Child-Pugh A or B, or the standard is achieved with medical liver care. (4) Sometimes, for single tumors >5cm in diameter that cannot be surgically resected, or multiple tumors with maximum diameter >3cm, local ablation can be part of palliative comprehensive treatment, but it needs to be strictly controlled. 3.Which tumors are not suitable for local ablation treatment? ① Huge tumors or diffuse hepatocellular carcinoma; ② Combined with portal trunk to secondary branch carcinoma thrombosis or hepatic vein carcinoma thrombosis, adjacent organ invasion or distant metastasis; ③ Tumors located on the visceral surface of the liver, more than 1/3 of which are exposed; ④ Liver function classification of Child-Pugh grade C, which cannot be improved by liver protection treatment; ⑤ Bleeding from ruptured esophagogastric fundic varices within 1 month before treatment; ⑥ Uncorrectable coagulation (6) uncorrectable coagulation disorders and obvious blood abnormalities with obvious bleeding tendency; (7) persistent massive ascites and malignant fluid; (8) combined with active infection, especially inflammation of the biliary system; (9) failure of important organs such as liver, kidney, heart, lung and brain; (10) patients with impaired consciousness or unable to cooperate with treatment. Meanwhile, tumor in the first hilar region should be a relative contraindication; tumor close to the gallbladder, gastrointestinal, diaphragm or protruding from the hepatic peritoneum is a relative contraindication to the percutaneous puncture route; intrahepatic lesions with extrahepatic metastases should not be considered as absolute contraindications, and sometimes local ablation therapy can still be considered to control local lesion development.