Radiofrequency ablation (RFA) is a technique that uses high-frequency electrical energy, delivered through a thin instrument (a "probe"), to destroy tumors that cannot be removed by traditional surgery.
RFA is used for the treatment of hepatocellular carcinomas (HCC) of the liver, when these tumors are small and the patient is not an appropriate candidate for surgical removal or liver transplantation. RFA may also be used in liver cancers that started in other parts of the body and have spread (metastasized) to the liver.
You may receive drug treatment before the ablation to stabilize the disease. Drug treatment can help reduce the size of the tumor. This helps make the ablation procedure easier and increases the chance of destroying the tumors.
The maximum size for a liver tumor to be treated with RFA has not yet been unambiguously established. However, many studies seem to indicate that RFA has optimal results for lesions smaller than 5 cm. Larger tumors may require more than one session.
Preparation
You may be advised to stop taking blood-thinning medications prior to the procedure and not eat or drink for a few hours beforehand. Depending on the type of RFA that is performed and whether or not anesthesia is required, you may be able to go home after the procedure or be hospitalized for at least one night in the hospital.
Procedure
Imaging methods such as CT (computed tomography), ultrasonography, or MRI (magnetic resonance imaging) are used to guide the probe into the tumor area. The probe is in the form of a long needle electrode through which a high-frequency electrical current is passed.
RFA can be done in a number of ways, using local anesthesia or general anesthesia (usually if the RFA is done during surgery).
- during open surgery (laparotomy)
- during laparoscopic surgery : in both cases the procedure is performed by hepatobiliary surgeons
- as a percutaneous (through the skin) procedure: in this case, RFA is performed by interventional radiologists. It is performed under local anesthesia, in which the probe insertion site is numbed. Typically, a venous line is taken for administration of fluids and medications, and the patient is connected to monitoring devices to measure heart rate and blood pressure.
In all cases of radiofrequency ablation, the probe is inserted (with radiological guidance by ultrasound or CT) into the tumor; once the optimal position is reached, the electrodes are activated and emit local heat, dissolving adjacent tissue (in a process known as coagulative necrosis). The probe is left in the site to be thermoablated for about 8-15 minutes: the time varies depending on the density of the nodule and its dimensions. For larger tumors, it may be necessary to change the position of the probe in different areas of the tumor.
To verify that all tumor tissue has been cauterized, imaging tests are done a few hours to a few weeks after the procedure.
Side effects
RFA is generally well tolerated and does not usually cause any severe pain after the procedure. There is a very low risk of bleeding, infection, or injury to the gallbladder or bile ducts. You may have a mild fever and flu-like symptoms after the procedure for a few days.
Effectiveness
Most studies indicate that ablation is more than 85% successful in destroying small liver tumors and that more than half of tumors removed by radiofrequency ablation do not recur. Because treatment usually does not cause serious health risks, chemotherapy can be resumed (if necessary) soon after the procedure. Radiofrequency ablation usually has few complications and can be repeated as needed for the same tumor or if other tumors arise.