Radiofrequency Tumor Ablation
Using a catheter to apply RF energy to a tumor
to heat and destroy it
For many years, cancer specialists including clinician-researchers have used radiofrequency (RF) probes to destroy tumor tissue. Interventional radiologists have refined this approach in recent years to make it available to more patients and to make it easier to deliver.
RF tumor ablation spares
patients the surgery that would otherwise be necessary to treat or remove tumors.
RF tools transmit radiowave energy at high levels through small areas of tissue. The tissue absorbs the energy, converting it to heat. This heat destroys the cells exposed to it. Specialists can, thus, place the tip of RF delivery devices in and around tumors to destroy all or part of these masses. Using this approach, interventionalists can remove (kill) tumors without resecting (cutting) them or can, at the very least, slow the growth of these tumors. As a result, the technique gives
them a way to treat tumors without conventional open surgery.
RF tumor ablation is a highly targeted procedure, directed at specific cancer masses. Aria specialists use high-resolution CT scanning instruments at them during the treatment. They may also use CT fluorscopy or othervarious forms of angiography. Interventionalists introduce the RF probe as a small, needle electrode inserted through the skin and into the tumor tissue. The RF energy delivered by this device also closes off small blood vessels around tumors as it destroys the cells within them, even further decreasing the chance of bleeding when compared to traditional surgery. Dead tumor tissue shrinks and forms a scar.
Currently, RF tumor ablation is not a replacement for other types of cancer treatments for which a patient may be an eligible candidate. RF ablation is in use only for a certain group of patients, those who:
• cannot medically undergo surgery or otherwise are not candidates for surgery;
• have small, early-stage cancer; previously treated primary cancer; or metastatic cancer with a very limited number of metastatic tumors;
• and do not have other treatment options.
At present, RF tumor ablation has two primary applications:
• Radiofrequency ablation of lung tumors. At our center, lung tumors are the most frequent target for RF ablation. Aria specialists use the RF tool to destroy specific, identified tumor masses in the lung wall. While several other leading cancer centers in the Delaware Valley are beginning to offer this option, Ariais the only center performing this procedure on a regular basis. RF ablation has much less impact on the patient's lung function than does standard surgical removal of the tumor. This can be important for those who already have impaired ability to breath.
Most patients who undergo RF ablation for lung cancer will also receive radiation therapy treatments in the weeks or months following, with the goal of further destroying remaining cancer cells in the area.
• Radiofrequency ablation of liver tumors. For many patients who have liver cancer, surgery is not possible because of the extent of the tumor (more than one tumor in disparate locations of the liver) or the presence of cirrhosis that poses an excessive risk of liver failure after the surgery. Interventionalists can combat liver tumors in these patients with RF ablation. Sometimes the team will use this treatment to treat small tumors in conjunction with surgery of a large mass elsewhere in the liver.
The main targets have been two types of liver cancer: primary liver cancer (hepatocellular carcinoma or hepatoma) and metastatic liver cancer (most often colon cancer that has spread to the liver). Tumors of these types (that are 4 cm. or smaller) are subject to treatment by RF ablation.
The treatment has shown excellent results in treating primary liver tumors. In part because these tumors tend to be slow growing and encapsulated (enclosed within a capsule inside the liver), they have been especially responsive to RF ablation.
As for tumors that have metastasized to the liver from other cancers,there has traditionally been no effective treatment for the vast majority of patients. Most such cancers are already beyond surgical treatment at the time they are found. And even those patients who undergo surgical removal of such cancers often experience recurrence. This has left a very large group of cancer patients with no treatment option. But in recent years, RF ablation has been effective for patients with small, solitary liver metastases. In some cases, RF ablation even has the potential to help make a patient a surgical candidate, by treating small tumors that, because of their positions, are too difficult remove through an operation alone.
RF tumor ablation has also begun to enter use for treating cancer of the kidneys, bone, soft tissues, adrenal glands, spleen, pancreas, prostate gland, and breast.<(Interventionalists may also sometimes apply RF ablation to benign masses or growths such as cysts.)
RF ablation is considered a minimally invasive approach to accomplishing a surgical goal. For the RF procedure, patients normally need sedation only in addition to local anesthesia. They will undergo the procedure as an outpatient or with a brief overnight stay.
Discomfort after the procedure is mild enough that oral pain medication can control it. Most patients resume normal activities with a day or two of treatment. There is no residual soreness or other discomfort for most patients after approximately a week following the procedure. And, interventional radiologists can repeat RF ablation multiple times, if necessary to treat tumor recurrence –– or for larger tumors or ones that are difficult to reach.
After undergoing RF tumor ablation, patients receive additional CT scanning or other imaging to assess the results. RF ablation can be effective in debulking a tumor (or reducing its size), so that treatments such as chemotherapy or radiation therapy can more readily kill remaining tumor cells. Furthermore, the cancer team can combine RF ablation with surgery, to treat a patient who has several tumors in different locations. Because recovery time from RF ablation is much shorter than from conventional surgery, patients can resume other types of treatment more quickly.
Local control of one or more tumors –– which RF ablation is one technique for accomplishing –– does not, of course, prevent a cancer from metastasizing to other locations. In results to date, though, RF tumor ablation has provided safe and effective treatment of localized cancer, with very low complication rates. It is also effective for relieving pain, which is usually the result of the tumor invading surrounding areas. And partly for this reason, it improves quality of life for patients who undergo this treatment. In addition, early data on RF tumor ablation is indicating that the treatment typically confers some additional survival time to patients.
As with any newer procedure, many more patients could be benefiting from radiofrequency tumor ablation if they, and referring physicians, were aware of it. Currently, RF ablation is a treatment option available almost exclusively at large, urban, university-associated teaching hospitals; but, Aria's advanced interventional group makes it available to you in a community setting, with the same level of quality and precision as at larger medical centers.