Radio Frequency Ablation treats cancer
A new procedure called Radio Frequency Ablation (RFA) uses radio waves to fight the onslaught of cancer in the lungs. While RFA is mostly a palliative treatment, the good news is that the procedure is non-invasive; heat directly applied to the tumor through a needle-fine probe does the job.
Lung cancer kills more patients than any other cancer in the United States.
According to statistics from The National Cancer Institute website, 161,840 people died from lung cancer last year.
Almost 20 percent of patients with lung tumors are too weak to undergo surgery. Age may be a limiting factor or they may have serious conditions like emphysema, which is characterized by the stiffening of lung tissue. Since such patients are unfit to take the rigors of anesthesia, incisions, and surgery, they make good candidates for RFA procedures.
In an RFA procedure, under the guidance of a computed tomography (CT) scan, the surgeon inserts the RFA needle through the skin at the site of the tumor, aiming for its center. The needle is attached to a probe that allows the surgeon to have a detailed look inside the tumor and surrounding tissue. The other end of the RFA probe is connected to a generator, which produces an alternating current in the radio frequency range, which is around 3 kHz to 300 GHz. This current generates heat greater than 65°C. The target temperature is reached about 15 minutes into the procedure.
The high heat kills the cancer cells instantaneously. The surgeon then slides the needle out, and if all goes well, the patient will drive home in a couple of hours with two little bandages and a sore back.
Ghulam Abbas, a thoracic surgeon at the Heart, Lung, and Esophageal Surgery Institute at University of Pittsburgh Medical Center, is one of the pioneers of RFA for lung programs at UPMC. “This procedure is not an alternative to surgery,” said Abbas. “We offer it to very sick patients. They know their options when they come to us. They can’t go through surgery, as they might get into complications because of their illnesses. They take a risk with the disease.”
Oncologist Kiran Rajasenan, who also works at UPMC, has had several cancer patients who have undergone the RFA procedure. “I call it a breakthrough treatment,” he said. “I have some cancer patients who are 80 years [old] or more and they are afraid of any treatment. Dr. Abbas did the RFA procedure on them and the first thing out of their mouths was ‘I can’t believe it’s over!’”
After the procedure, doctors watch out for a collapsed lung or pneumothorax, which may occur in about 15 percent of the patients.
“Lungs are like sponges,” Abbas said. “Every time we breathe, the lung comes up to the chest wall and then subsides. Sometimes the RFA needle will cause an air leak from the lung. The air gets trapped between the lung and chest wall and puts pressure on the lung.” Doctors drain out the air and patients usually recover in a day. Patients follow up with CT scans after three and six months to gauge tumor size.
Although RFA can be beneficial to many patients, one of the drawbacks of this procedure is that most insurance companies will not cover it because they still consider it to be an experimental procedure. Last December, the Food and Drug Administration published data on RFA mortality that raised some eyebrows.
Though no statistics were mentioned, the FDA recommended that doctors concentrate on patient selection while performing this procedure. It also asked the doctors to perform clinical trials.
“Anyone can do a RFA procedure, but some doctors are more trained to handle complications,” Abbas explained. “Statistics would be better if thoracic surgeons were doing the RFA procedure. We can manage complications like massive bleeding or lung injury.”
The technology still needs tweaking and only deals with tumors smaller than three centimeters.
According to Abbas, “RFA works best at the center of the tumor; however, tumors grow faster on the edges, so RFA does not work all the time.
“We are trying to find the right ablative combination which attacks the tumor on the edges and its center.”
The RFA procedure has not been widely used because it requires highly trained surgeons and high-tech equipment.
According to The Journal of Thoracic and Cardiovascular Surgery, about 2300 lung cancer patients have undergone the procedure, but there is still not enough evidence to prove that the procedure has positive results.
The conventional treatment of localized lung cancer is performing a surgery. The surgery is followed by chemotherapy or radiation.
The thoracic surgeon will do a lobectomy, which is a surgery to remove the diseased part of the lung.
Chemotherapy is used after the surgery to kill off any remaining cancerous cells.
Lobectomy is a major surgery requiring a hospital stay, general anesthesia, a major incision, and frequent risks. Abbas mentioned that about 2 percent of the patients who undergo lobectomies die from complications.
Also, after surgery, the patients’ lung function is affected. Normal activities like climbing stairs become harder.
Abbas also mentioned that even after surgery and chemotherapy, patients have slim chances: Only about 15 percent of the patients survive after five years.
RFA procedures are based on a different philosophy of palliative care.
They assume that patients are not aiming for a long lifespan and try to make their remaining time independent and comfortable.
Hence, although RFA treatment can be beneficial, it is not advisable for young patients.
Treating lung cancer will be much easier if the cancer is detected early.
Jill Siegfried, co-director of the lung and esophageal cancer program at the University of Pittsburgh Cancer Institute, believes that currently there are no good methods for detecting lung cancer.
“Sometimes the tumor may be hidden behind the heart or major vessels and may be hard to see,” she said.
Siegfried and her team are searching for a way to develop a blood test for cancer.
Some cancer cells secrete proteins in the blood serum; Siegfried is trying to find a link between these proteins and growth of cancer cells.
“We are still about 10 years away from a blood test for cancer,” she said.
Until a blood test comes along, RFA will be a helpful procedure for older lung cancer patients who are not able to undergo surgery.