Percutaneous therapies show success, but more research is needed on long-term outcomes

January 1, 2002

Radio-frequency ablation has evolved from a mere palliative measure to standard procedure for treating unresectable liver tumors. Research presented at the 2001 RSNA meeting suggests it eventually may replace surgery altogether.

Radio-frequency ablation has evolved from a mere palliative measure to standard procedure for treating unresectable liver tumors. Research presented at the 2001 RSNA meeting suggests it eventually may replace surgery altogether.

Authors from the U.S. and abroad touted the benefits of RFA alone or in combination with other percutaneous therapeutic techniques, such as microwave coagulation, acetic acid and ethanol injection, cryoablation, or chemoembolization. Despite the promising results, however, RFA remains a difficult sell to specialists in other fields who want to see hard data.

"When you move outside radiology and discuss it with pathologists, oncologists, and surgeons, what they want to see are survival rates, among other things," said Dr. Riccardo Lencioni, a radiologist at the University of Pisa in Italy.

Two-thirds of the audience at one of the RSNA's gastrointestinal sessions validated the procedure as safe and accurate when the floor was opened for discussion. Almost unanimously, they said RFA was their interventional procedure of choice in treating patients with liver cancer.

Improved survival data should make the procedure easier to promote. In a study presented by Dr. Tito Livraghi, chief of radiology at Vimercate in Milan, Italy, the survival rate observed for one, three, and five years, respectively, was 95%, 81%, and 70% for RFA combined with other therapies.

A team lead by Lencioni compared RFA with percutaneous ethanol injection (PEI) in the treatment of hepatocellular carcinoma (HCC). The Italian researchers assessed 102 patients with solitary HCC smaller than 5 cm or a maximum of three lesions 3 cm or smaller. They found that RFA and PEI have a similar short-term survival rate, but RFA is superior for local recurrence-free survival.

Researchers from France and Germany also presented work on other ablation techniques, including good results with CT-guided direct application of a new cisplatin/epinephrine gel to ablate unresectable liver tumors.

RFA and other percutaneous therapeutic techniques should be considered complementary to one another in order to obtain better survival rates than those obtained with single treatments, according to Livraghi. Although RFA's long-term survival rate and statistical predominance over other therapies in the treatment of unresectable liver tumors make some radiologists consider it an alternative to surgery, he pointed out the necessity of careful selection and combination of therapies.

When experienced surgeons are confident they can perform anatomical resection of a single tumor without mortality, surgery is still the best option. But the number of surgeons known to Livraghi who can guarantee this kind of result is very small.

"I believe that radiological treatments are better," he said.

On a more cautionary note, specialists such as Dr. Gerald Dodd, chair of radiology at the University of Texas, San Antonio, and one of the moderators at the RSNA's gastrointestinal sessions, believe that better evidence is needed before considering RFA a replacement for surgery.

"There are neither enough hard data nor randomized trials to maintain that RFA is as good as surgery," Dodd said.