Minimally invasive techniques for liver cancer Since liver lacks nerves and has no pain sensation, early symptoms of liver cancer are not obvious, and most of the cases are found in the middle or late stage. Surgical resection is still the basic treatment method for liver cancer, which has changed from an “incurable disease” to a “partially curable disease” over the past 100 years. In the past 100 years, liver cancer has changed from an “incurable disease” to a “partially curable disease”, and minimally invasive treatment offers the possibility of radical treatment for some advanced liver cancer patients who cannot be surgically resected. Percutaneous radiofrequency ablation therapy Percutaneous radiofrequency ablation therapy is to insert needle electrodes with sheaths accurately into the tumor under the guidance of ultrasound or CT and use the high temperature generated by radiofrequency to cause coagulative necrosis of cancer cells. Radiofrequency ablation therapy has certain curative effect on metastatic liver cancer. Percutaneous cryoablation therapy Percutaneous puncture cryotherapy for liver cancer is one of the methods that have been proved to be effective in recent years. Liquid nitrogen or argon gas is often used as cryogenic agent. Percutaneous puncture is to accurately insert the cryoprobe into the tumor under the guidance of ultrasound, CT or MRI. At present, argon helium knife or liquid nitrogen freezing system is mostly used for treatment, and generally two cycles of freezing and thawing can cause complete death of cancer cells.