Physicians perform minimally invasive procedures using imaging guidance to destroy liver tumors. Several procedures can benefit patients with liver cancer.
Physicians in the Liver Cancer Program use a variety of minimally invasive treatments for destroying liver tumors using heat or cold energy. These local ablation procedures are typically used to treat well defined small tumors that cannot be surgically removed. However, ablations can also be performed as part of an open surgical procedure or a minimally invasive liver surgery procedure (laparoscopic liver surgery). In some cases, superficial tumors can be resected, while deeper tumors are destroyed by ablation, thereby preserving most of the liver tissue.
Radiofrequency Ablation (RFA)
Using ultrasound or CT guidance, an electrode-tipped probe is positioned inside the liver tumor. A radiofrequency current is then passed through the electrode, creating energy that destroys (or ablates) the tumor tissue near the probe tip. The energy also closes small blood vessels, minimizing the risk of bleeding.
This procedure uses cold energy to freeze and destroy tumor tissue. The probe is positioned within the tumor using imaging guidance and cooled to -190° C (-360° F), engulfing the tumor within an ice ball and resulting in the death of tumor cells. The physician can easily monitor the margins of the ice ball with ultrasound or CT imaging and adjust the probe output as needed. Because of this ability to monitor and control the ablation zone, cryoablation can be used to treat tumors that are close to critical structures.
Liver tumors that are adjacent to a large blood vessel can be difficult to treat with RFA and cryoablation. The large volume of blood flowing past the ablation zone tends to cool (or warm) tumor tissues, preventing them from sustaining cancer-killing temperatures. Microwave ablation technology achieves higher temperatures more quickly than other options, which facilitates treatment of tumors near large vessels.
Microwave ablation uses the heat-producing power of microwave energy to destroy cancerous tumors. A probe-like antenna inserted into the center of a tumor transmits electromagnetic waves, which cause water and other molecules within the tumor to vibrate many thousands of times a second. This action generates friction and heat that kill cancer cells.