Updated data indicate that ultrasound-triggered microbubble destruction (UTMD) may play an effective role in improving outcomes for hepatocellular carcinoma (HCC) when paired with Y-90 radioembolization.
“This is a long-standing project that’s been spearheaded by both Kevin Anton, MD, PhD, and John Eisenbrey, PhD,” said Victor Rivera, MD. “They’re looking at contrast-enhanced ultrasound, which induces cavitation or destruction of the microbubbles of the contrast agent in the setting of these patients who are undergoing radioembolization for HCC.”
Dr. Rivera, lead author of “Update on the Use of Ultrasound Microbubble Destruction for Improving Radioembolization Therapy of Hepatocellular Carcinoma,” said that while previous literature looked at the role of contrast-enhanced ultrasound for perfusion or vascularity of these tumors, this research seeks to better understand what the destruction of these microbubbles does to the efficacy of radioembolization in this particular patient population.
“I think a lot of folks who go into interventional radiology are at some point drawn to locoregional therapy for HCC or other kinds of malignancies,” Dr. Rivera said. HCC itself is a leading cause of cancer mortality in the United States, and the number of patients who are candidates for transplant is very low relative to the incidence of the disease.
“Locoregional therapy can be an excellent option for patients who are unable to receive a transplant,” he said, “and anything that can improve its efficacy will not only advance patient care, but the field of IR in general.”
HCC patients were assigned to either an experimental arm that received UTMD and transarterial radioembolization (TARE), or a control arm of TARE alone. Patients in the experimental arm received USMD at 1–6 hours after radioembolization, and again at 7 and 14 days. Both arms received follow-up at 2–8 months using standard imaging surveillance by two blinded diagnostic radiologists posttreatment.
Of the patients within the control arm (40), 37% had stable disease and 63% had a partial or complete response at follow-up. In the experimental arm (38 patients), 5% had stable disease and 95% had a partial or complete response.
“The safety profile of the contrast agent itself has been demonstrated in prior studies and we know it’s well tolerated by patients,” said Dr. Rivera. “In terms of adverse events in this particular study, the experimental arm seems to have a slightly higher incidence of postembolization syndrome, which is a well-described phenomenon when it comes to our embolization patients.”
Dr. Rivera theorizes that this is likely related to the more pronounced inflammatory response generated by the microbubble destruction, explaining that as the microbubbles inside the tumor get cavitated and destroyed, damaged cells may release inflammatory markers that induce that embolization syndrome. “The good news is that this is transient,” he said. “It doesn’t result in any permanent deficits or injury. In terms of long-lasting harm or adverse events, I don’t think there is any difference between the two treatment arms.”
According to Dr. Rivera, the data—including the adverse event effects—not only shows that the technique is well tolerated and safe, but also helps physicians better understand the mechanism by which radioembolization works and clarifies what’s happening on a cellular level.
It also lays the groundwork for studying the effects of this technique past standard of care for this patient population, Dr. Rivera said.
“This technique ticks off a lot of boxes in terms of patient comfort and safety, with the added benefit of potentiating the effects of their therapy,” he said. “And this has been an exciting opportunity to see how we can improve an established, efficacious treatment for patients. I’m eager to see what this means for our patients.”
