Radiofrequency Ablation (RFA) of the Liver

Radiofrequency ablation (RFA) is a technique that uses high frequency electrical energy that creates heat, delivered through a thin instrument known as a probe, to destroy tissue. It is used in the liver to destroy tumors (either primary liver cancers or cancers that have metastasized or spread to the liver) that cannot be removed by traditional surgery.

Radiofrequency ablation also is  used in many other medical conditions. Examples of other uses of radiofrequency ablation include:

• The management of lumbar or low back arthritis pain by ablating nerve tissue to reduce pain signals
• Destruction of areas of the heart that cause abnormal heart rhythms (arrhythmias)
• Treatment of varicose veins
• Destruction of tumors in other sites of the body, including the esophagus, kidney, lung, and prostate.

Radiofrequency ablation is used to treat hepatocellular carcinomas (HCC) of the liver, primary cancers that arise in the liver cells, when these tumors are small and the patient is not an appropriate candidate for surgical removal of the tumor or liver transplantation. Radiofrequency ablation also can be used on liver tumors that have originated elsewhere in the body and have spread (metastasized) to the liver.

The maximum size for a liver tumor to be treated by ablation has not been established. However, radiofrequency ablation is best suited for tumors less than 5 cm. Larger tumors may require more than one session.

Your doctor will give you specific instructions on how to prepare for the procedure. You may be advised to stop taking blood-thinner medications before the procedure and not to drink or eat anything for some hours beforehand. Depending on the type of radiofrequency ablation that is done, and whether or not anesthesia is required, you may be able to return home after the procedure, or you may remain overnight in the hospital.

Imaging procedures like CT (computed tomography) scan, ultrasound, or magnetic resonance imaging (MRI) are used to help guide the probe into the area of the tumor. The probe is designed like a long needle electrode through which a high-frequency electrical current is passed.

Radiofrequency ablation can be performed in different ways. It may be administered during open surgery, laparoscopic surgery, or percutaneously (through the skin) using imaging studies to guide the placement of the probe. Interventional radiologists are the doctors who most commonly perform RFA through the skin, while surgeons may perform RFA during laparoscopic or open surgeries.

In all cases of radiofrequency ablation, a probe is inserted into the center of the tumor and the non-insulated electrodes, which are shaped like prongs, are projected out from the central probe into the tumor. The local heat that is generated melts the tissue (in a process known as coagulative necrosis) that is adjacent to the probe. The probe is left in place for about 10 to 15 minutes. For larger tumors it might be necessary to re-position the probe in different areas of the tumor. Imaging studies are done anywhere from a few hours to weeks after the procedure to ensure that the entire tumor tissue has been cauterized.

Radiofrequency ablation may be done using local anesthesia or general anesthesia (typically if RFA is performed during surgery). Radiofrequency ablation performed by inserting the needle probe through the skin can be done under local anesthesia in which the skin insertion site is numbed. Typically, an intravenous line is placed for delivery of fluid and medications. Monitoring devices to measure heart rate and blood pressure are attached to the body.

Each radiofrequency ablation typically takes 10-30 minutes. Ablating more than one area requires more time. The entire procedure is usually finished in 1-3 hours. After the procedure, the patient remains in a recovery room until fully awake.

Radiofrequency ablation is generally well-tolerated, and does not typically cause any serious pain after the treatment. There is a very low risk of bleeding or infection after the treatment as well as a low risk of injury to the gallbladder or bile ducts. Sometimes, a low-grade fever and flu-like symptoms may be present after the procedure for a few days.

 Other possible side effects of radiofrequency ablation include

• post-procedure pain,
• inflammation of the gallbladder, and
• injury to the bowel.

In most studies, radiofrequency ablation is over 85% successful at destroying small liver tumors. Studies also show that over half of the tumors removed by radiofrequency ablation do not recur (come back). Because the treatment typically does not cause serious health risks, chemotherapy can be resumed (if needed) soon after the procedure. Radiofrequency ablation usually has few complications, and can be repeated if necessary for the same or additional tumors.