Percutaneous Thermal Ablation Offers a Safe Treatment Option for Small Liver Tumors
Meta-analysis reveals low rate of major complications
A minimally invasive treatment for small liver tumors is proving to be not only effective, but consistently safe. In a study published in Radiology, French researchers reviewed 15 years of prospective data from 49 studies and concluded that percutaneous thermal ablation of malignant liver tumors resulted in few serious adverse events (AEs) and a 90-day mortality rate of just 0.01%.
“What stood out most was how stable the safety profile remained, even though ablation is now used more broadly and in more complex settings than before,” said lead author Gary Doppelt, MD, from the Department of Radiology, Caremeau University Hospital, Nîmes, France, and the University of Montpellier in France.
The researchers note that the findings provide an updated safety benchmark for the procedure. They emphasized that a clearer picture of the baseline safety profile of ablation could help guide treatment decisions and inform future studies of its use alongside other therapies.
Defining Modern Safety Benchmarks
Dr. Doppelt led a team of 15 French doctors with a range of expertise, including interventional radiologists with strong experience in liver ablation as well as colleagues with expertise in epidemiology, statistics and clinical research methodology.
Their goal was to define solid contemporary benchmarks for major complications and procedure-related mortality. To do that, two investigators independently screened the studies, extracted data and assessed the risk of bias.
The review included studies published between January 2007 and September 2022 that reported AEs after radiofrequency or microwave ablation. The studies specifically focused on ablation of three or fewer liver tumors measuring 5 cm or smaller and included a follow-up period of at least 90 days.
“We expected ablation to remain a very safe treatment, but we wanted to measure that precisely using prospective data rather than assumptions or older retrospective series,” Dr. Doppelt said.
He added that the need for updated benchmarks reflects how much the field has changed in recent years.
“Percutaneous thermal ablation is now a major treatment option for small liver tumors, but the safety benchmarks most people still cite come from older studies,” Dr. Doppelt said. “Because both the technology and the indications have evolved, we felt it was important to provide an updated picture of how safe ablation really is in contemporary practice.”
Safety and an Evolving Role in Treatment
Dr. Doppelt believes the team’s findings give radiologists and multidisciplinary teams a strong, contemporary safety reference when discussing curative therapy for small malignant liver neoplasms.
“For patients, the message is important: In modern practice, percutaneous thermal ablation is a minimally invasive treatment with a very low risk of major complications and extremely low procedure-related mortality,” he said.
Still, questions remain about how ablation fits into the broader treatment landscape. Evidence from prospective randomized trials on colorectal metastases and hepatocellular carcinoma suggests that thermal ablation can achieve outcomes comparable to surgery in select patients, particularly for small lesions. Michael A. Bettmann, MD, professor of radiology emeritus at Wake Forest University School of Medicine in Winston-Salem, NC, said the curative ability of the treatment remains unclear.
In a related editorial, Dr. Bettmann stated that surgery is the only therapeutic approach to hepatocellular carcinoma that may be considered curative. He added that the prognosis for both primary and metastatic liver cancer is poor overall, and that even surgery that involves resection or transplant yields a five-year survival rate of less than 50%.
“Thermal ablation is most logical, theoretically, for use with a limited number of lesions that originate in the target organ—in this case, the liver,” Dr. Bettmann explained. “If lesions are metastatic, ablation can be combined with other treatments, such as systemic medication.”
Further Clinical Trials Needed to Determine Best Use
Dr. Bettmann said that future research will almost certainly include a comparison of different methods: radiofrequency ablation, cryoablation, microwave ablation and US ablation.
“All have shown considerable efficacy, but there are so many variables that it is very hard to reach firm conclusions,” Dr. Bettman said. “Further, ablation is rarely used alone. Determining how to best use it in conjunction with radiation, arterial embolization techniques or—most importantly—targeted systemic therapy will be the major focus of clinical research.”
Dr. Doppelt agrees that future clinical trials need to examine how radiologists can combine ablation with systemic therapies such as immunotherapy.
“If we know the baseline safety profile of ablation itself, it becomes much easier to interpret adverse events in combination studies and to design future trials more rigorously,” he concluded.
For More Information
Access the Radiology study, “The Safety Standards for Liver Percutaneous Thermal Ablation: A Meta-Analysis of Adverse Events over 15 Years,” and the related editorial, “Ablation of Liver Malignancies Is Safe: Does This Fully Define Its Role?”
Read previous RSNA News articles on thermal ablation: