Radiofrequency ablation and other modalities for non-surgical ablation of liver tumors
Ablation refers to any method that physically destroys a tumor. Ablation does not involve surgical removal of the tumor. Ablation is usually done for one or two small tumors in the liver. When the tumors are larger and more in number, ablation techniques are not effective and a different method such as Trans-arterial chemoembolization (TACE) must be used.
Radio-frequency ablation (RFA)
In Radio-frequency ablation, a probe is inserted through the skin and liver into the center of the tumor either under ultrasound or CT scan guidance. There are electrodes within the probe in which heat is generated locally by high frequency radio waves. The local heat burns the cancer tissue. The probe is left in place for about 10-15 minutes. The whole procedure is monitored visually by ultrasound scanning. Single liver tumors less than 5 cm in size are best suited for RF Ablation. In some patients, to achieve a better response, this procedure has to be done laparoscopically through small holes in the abdominal wall.
Percutaneous ethanol (alcohol) injection
In this technique, pure alcohol is injected into the tumor through a very thin needle with the help of ultrasound or CT guidance. Alcohol induces tumor destruction by dehydrating and destroying cancer cells. Alcohol injection is less effective than RF ablation. It may take several sessions to completely destroy the cancer. The most common side effect of alcohol injection is leakage of alcohol into the abdominal cavity, thereby causing pain and fever.
Cryoablation is similar to RF Ablation. Like RF Ablation, a probe is inserted through the skin and liver directly into the cancer. Instead of using heat, cryoablation uses liquid nitrogen to freeze the tumor and kill it. This technique is as effective as RF Ablation and can be used in some tumor locations where heat might accidentally damage adjacent organs (like when the gallbladder or colon is too close to the tumor).