At its most basic, tumor ablation is a method of destroying a tumor without major surgery. A needle electrode inserted inside the tumor produces either extreme heat or extreme cold, which destroys the tumor from the inside out. The treatment is focused on a very small area, so only the tumor itself is affected. Your doctor may also choose to treat a small margin of tissue around the tumor to prevent a recurrence. The majority of healthy tissue in the organ is unharmed.

Because RFA is the most common method of destroying tumors, we’ll look at the equipment and procedure for this method.

The Equipment
• Generator and grounding pads
Your body will be made into an electrical circuit—that’s what helps produce the energy that heats and kills the tumor. A generator that the needle electrode is attached to will produce the energy that causes the heat, while grounding pads on your body will complete the circuit, allowing the needle electrode to destroy the tumor.

• Imaging
Your doctor will use imaging technology, such as ultrasound or a CT scan, to guide a needle electrode to the tumor. Ultrasound produces no radiation, although CT does.

• Needle electrode
Most RFA treatments use a 14 to 17.5-gauge needle. The needle is an electrode composed of an insulted shaft and a “live” tip, through which the energy will flow. Some RFA needles also have umbrella-like prongs that will extend from the tip and penetrate more of the tumor. Some needles are also water-cooled around the shaft, which allows for more even heating at the tip and reduces the risk of unwanted charring of tissue outside of the tumor.

The Procedure
You may be given a local or general sedative before the procedure. Your doctor will locate the cancerous cells with ultrasound, CT, or MRI, and guide the needle electrode into the tumor. The grounding pads will be attached to an area on your body near the needle electrode insertion site. The doctor will activate the generator, causing the needle electrode tip to begin emitting radio waves. The destruction process will probably take between 10 and 60 minutes. Your doctor may then relocate the needle electrode to heat another tumor or another area of the same tumor and repeat the process.

The needle electrode will be withdrawn, and the insertion site will be bandaged. Your doctor will not remove the tumor—the dead tissue will shrink and will gradually be replaced by scar tissue. Your doctor will monitor the tumor site with imaging technology to see if the tumor returns. If it does, RFA can be performed again without any major risks.

Cross sectional CT image shows needle electrode (straight line in center) inserted in a lung tumor. (Provided by Dr. Dupuy)

Who Can Benefit from RFA
• The patient profile
RFA and other forms of tumor ablation are safe for patients who may not be viable candidates for surgery. For example, patients who cannot undergo surgery because they face an increased risk of bleeding can safely use RFA. It is minimally invasive, and the use of heat actually decreases the risk of bleeding because the heat cauterizes nearby blood vessels. Patients who are too frail for major surgery can also benefit from RFA and other ablative methods.

• Inoperable tumors
Similarly, RFA can be used to treat tumors that cannot be treated with surgery. Many liver tumors, for example, are inoperable because too much healthy tissue would be destroyed in the process of removing the tumor and not enough healthy tissue would be left to allow continuing function of the liver. But RFA does not harm the healthy tissue surrounding the tumor, so it can successfully treat tumors that cannot be reached with surgery.

Location of Tumors
RFA is FDA-approved for treatment of liver tumors, and it is being successfully used to treat tumors in the kidney, breast, bone, lung, lymph nodes, nerve ganglia, and soft tissue.

Size of Tumors
RFA is most successful at eliminating tumors that are between 0.5 and 3 centimeters in size. RFA can also be used to de-bulk larger tumors, making them more susceptible to other treatments, such as chemotherapy and radiation therapy.

Number of Tumors
RFA has been most successful in treating three or fewer tumors per organ. The procedure can be used to treat more tumors in a site, but survivability rates are lower.

Pain Management
Finally, RFA can be used to reduce or eliminate painful metastatic bone tumors that cannot be treated with other methods. In this case, RFA is used for pain management, not to eliminate the original cancer causing the bone tumors.