Ablation for Liver Cancer

Ablation destroys the tumor without removing it. The doctor places needles into the tumors and kills the tissue next to the needles by injecting alcohol or by heating or freezing the cells. The placement of the needles is usually guided by CT scans or ultrasound. In some cases, the needle is inserted during surgery or laparoscopy. However, ablation is usually done by an intervention radiologist who inserts the needle directly into the skin.

Ablation is a good option for patients with small liver tumors who cannot have their tumors removed by surgery.

The types of ablation used for liver cancer include:

• Radiofrequency ablation - This technique uses thin electrodes that release high-frequency, alternating electrical current. The doctor inserts a probe into the center of the tumor. The probe pushes the electrodes, which are shaped like prongs, further into the tumor. The electrical current that flows from the electrodes heats the tumor to 80° C to 100° C (coagulative necrosis), which kills the cancer cells. Radiofrequency ablation can be used to treat small liver tumors that cannot be removed by surgery. It is also used to treat some of the symptoms of metastatic liver cancer.
• Ethanol ablation (percutaneous ethanol injection, or PEI) - The doctor injects pure alcohol (ethanol) through a very thin needle into the tumor. The alcohol dries out the cancer cells, which kills them. Ethanol ablation can be used to treat small tumors or to reduce the symptoms of metastatic liver cancer. Five or six ethanol ablation sessions might be needed to completely destroy the cancer.
• Cryosurgery (cryotherapy) - The doctor uses liquid nitrogen to cool a stainless steel probe (cryoprobe). The very cold probe is then inserted into the tumor, where it is left for 15 minutes. This cools the surrounding tissue to minus 190° C, which kills the cancer cells. The area is thawed for 10 minutes and then frozen again for another 15 minutes. This technique does not affect healthy liver cells, so it has very few side effects. Cryosurgery can kill larger tumors than radiofrequency ablation or ethanol ablation. It is sometimes used in combination with surgery, chemotherapy, or other treatments.