Radiofrequency ablation shows promise in treating metastatic liver tumors
(SACRAMENTO, Calif.) -- Radio wave energy is nothing new to the operating suite. For years, surgeons have used radio wave electricity to cauterize blood vessels. More recently, it's been used to vaporize tiny lesions in the brain.
Now, two physicians at UC Davis Medical Center are using this familiar and minimally-invasive tool to eliminate primary and metastatic liver tumors, and having encouraging results.
Radiologist John McGahan and surgical oncologist Philip Schneider are pioneers in the use of radiofrequency ablation for metastatic lesions. The technique has several strategic advantages over traditional surgery. Because it can be done laparoscopically or percutaneously, the procedure has fewer risks and complications. In addition, a patient's hospital stay and their recuperation time is shorter. Radiofrequency ablation requires an overnight stay in the hospital; liver surgery requires a five to seven day stay. If re-treatment is needed, it can be done relatively easily.
It is especially effective in destroying tumors that can't be removed surgically, such as when a tumor is too close to the diaphragm, arteries or blood vessels. In cases where the liver is diseased or when the patient is too sick to undergo surgery, radiofrequency ablation offers an alternative where few exist.
"On selected patients, this technique has the same results as surgery but with much fewer complications," says Schneider, chief of the division of Surgical Oncology and associate director of clinical affairs for the UC Davis Cancer Center.
"Some patients may now have a chance at a cure that they may not have with surgery alone."
The two physicians are participating in a Phase II clinical trial to evaluate the effectiveness of this modality on patients with metastatic liver disease. M.D. Anderson Cancer Center, Fox Chase Cancer Center, UC San Francisco and the University of Utah are other participants.
McGahan and Schneider have collaborated on 25 treatments on about 12 cancer patients. Some have been disease-free for more than a year. Those who died of cancer were able to live longer and enjoy a better quality of life than they would have without the procedure.
Manny Gerlitz is one patient who has benefited from the technique. The 87-year-old Stockton resident came to the UC Davis Cancer Center for treatment of metastatic colorectal cancer in 1996. "My doctor said I had some spots on my liver and that I had six months to live," recalls Gerlitz, an active retiree fond of fly fishing and hunting. "He told me to get my affairs in order, and that there was nothing they could do for me. But I asked for a second opinion."
Oncologists at the UC Davis Cancer Center removed the diseased section of his colon and put him on a special form of chemotherapy, which eradicated all tumors but one in his liver. They didn't want to give him additional chemotherapy for fears of damaging the hepatic bile ducts. McGahan used radiofrequency ablation to destroy the tumor in December 1997. Gerlitz has been cancer-free ever since.
McGahan and Schneider hope to learn if the treatment can cure cancer as well as delay mortality. Some 150,0000 people in the U.S. are diagnosed annually with colorectal cancer; 25,000 of these develop tumors in distant sites. Of the latter group, McGahan and Schneider expect that 9,000 will be eligible for radiofrequency ablation.
The procedure involves long, steel needles about the size and width of a hypodermic needle. The needles are thin enough that they can be inserted through tiny slits in the skin of the abdomen. McGahan and Schneider watch the needles on images produced by ultrasound or a CT scanner.
Once the probes reach the tumor, physicians turn on the current which heats an elliptical metal ball at the tip of each needle. The electricity gently destroys tumor tissue. "It essentially hard-boils it," says Schneider.
After the tumors are gone, and assuming the primary tumor does not recur, patients can live disease-free for months or even years.
McGahan, professor of Radiology at the UC Davis Medical Center, has had an interest in radiofrequency ablation for more than a decade. His work got a boost a few years ago when private companies began making new electrodes designed specifically for radiofrequency ablation.
McGahan is encouraged by the results of radiofrequency ablation in the liver, and its applications for non-cancerous growths. Recently he used radiofrequency ablation to treat an osteoid osteoma -- a benign but painful bone tumor -- in the leg of an 11-year-old girl. The girl's parents objected to traditional surgery, McGahan related, since it would have left a scar and required a three-month recovery time. The father begged McGahan to try radiofrequency ablation on the tumor, since he had read a report in a medical publication that it would work. McGahan agreed.
"The girl came in experiencing great pain from the tumor -- we had to take her off aspirin before the procedure. We used CT to find the precise location of the tumor, drilled a tiny hole in the bone and ablated the tumor. By the next night, the girl felt no more pain. Within a week, she was back playing soccer. They could not keep her down."
That kind of success is something they hope to create in patients with metastatic disease.
The news release is posted at http://news.ucdmc.ucdavis.edu
Information about Dr. McGahan can be found at http://www-radiology.ucdmc.ucdavis.edu/jpm.html
Materials provided by University Of California, Davis Medical Center. Note: Content may be edited for style and length.
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