A recent clinical trial has demonstrated the effectiveness and safety of histotripsy, a non-invasive treatment for liver tumors. The #HOPE4LIVER trials, which assessed histotripsy for both primary and metastatic liver tumors, achieved their objectives for technical success and safety, paving the way for early clinical adoption of the procedure.
How Histotripsy Works
Histotripsy utilizes focused ultrasound to mechanically break down tumors. This non-invasive approach offers a potential alternative to traditional treatments like surgery, radiation therapy, targeted drug therapy, immunotherapy, or chemotherapy, which often carry significant side effects and lengthy recovery times. The technology was pioneered by University of Michigan faculty and students over the past two decades and received FDA approval in late 2023 as an alternative to traditional liver-directed cancer treatments.
Clinical Trial Results
The #HOPE4LIVER trial enrolled 44 participants with 49 tumors across the United States and Europe. The results, published in Radiology, showed a 95% technical success rate (42 of 44 cases), surpassing the performance goal of 70%. The procedure-related major complication rate was 7% (3 of 44 cases), below the safety goal of 25%. According to Mishal Mendiratta-Lala, M.D., clinical professor of radiology at the University of Michigan and lead principal investigator of the trial, at least two of the major complications may have been cancer-related and not device-related.
Advantages of Histotripsy
Histotripsy offers several advantages over traditional liver tumor treatments. As a non-invasive procedure using sound waves, it can overcome some limitations associated with thermal ablation, radiation, and surgical resections. The 95% success rate reported in this trial compares favorably to other local techniques, while the 7% complication rate falls within reported ranges for those techniques. The procedure is also relatively quick, taking only about an hour, and patients often experience shorter hospital stays and reduced need for pain medication.
Expert Perspectives
Zhen Xu, Ph.D., U-M professor of Biomedical Engineering, Radiology, and Neurosurgery, who invented histotripsy, expressed excitement about the clinical trial results. "I hope that the non-invasive nature, high precision, and capability to spare critical vessels and bile ducts will really improve the treatment for patients with primary and metastatic liver tumors, and many other tumor types in the future," said Xu.
David Kwon at Cleveland Clinic also noted, "Histotripsy’s an ultrasonic-based energy device. It causes a cavitation with the ultrasonic pulse waves, and that cavitation causes microbubbles, and it is those microbubbles that causes frictional force through the cells and the cells die because of the production and disappearance of these microbubbles."
Expanding Clinical Applications
Researchers anticipate that these results will lead to early clinical adoption, larger trials, and more detailed data on long-term outcomes. Currently, the University of Michigan Department of Radiology has partnered with hepatobiliary surgery in a multidisciplinary approach to treat patients with primary and metastatic liver cancer. Furthermore, clinical trials are now underway to explore its use in kidney tumors.
Baptist Health's Miami Cancer Institute was among the first to offer histotripsy post-FDA approval and was involved in the #HOPE4LIVER clinical trial. Govindarajan Narayanan, M.D., chief of interventional oncology at Miami Cancer Institute, highlighted that patients treated at their center experienced no immediate post-procedure pain and are doing well. He also noted the advantage of histotripsy, stating, "The advantage of histotripsy is that there are no incisions, no placement of needles or catheters, and no radiation... Histotripsy is another option for patients who are at high risk for surgery or who have failed other treatments."
