A study of 972 patients found that 69.8% of histotripsy procedures performed since FDA clearance in 2023 were for metastatic liver cancer rather than primary tumors, raising concerns about patient selection despite the procedure's favorable safety profile and low complication rates.
- 69.8% of histotripsy procedures were performed for metastatic disease, while only 30.2% treated primary liver malignancies
- Safety profile is strong: 88.4% of patients discharged same day, 92.3% by next day, with 30-day readmission rate of only 0.9%
- Colorectal cancer was the most common metastatic primary site at 26.7%, followed by pancreatic cancer at 12.4%
- Most procedures performed in outpatient settings with 851 of 972 patients treated in a single session
Most histotripsy treatments are performed for metastatic disease despite limited evidence suggesting its effectiveness, suggest findings published August 5 in JAMA Network Open.
Since receiving regulatory clearance in 2023, histotripsy has been most performed in the outpatient setting and with low rates of laboratory toxic effects and procedural complications, wrote a team led by Allan Tsung, MD, from the University of Virginia in Charlottesville.
“Our findings highlight the importance of understanding which patients are most likely to benefit as this promising technology is incorporated into routine cancer care,” Tsung told AuntMinnie.
Histotripsy, a focused ultrasound therapy, in 2023 received clearance by the U.S. Food and Drug Administration (FDA) for treating primary and metastatic liver tumors. This treatment option has a favorable safety profile and potential benefits in carefully selected patients.
Tsung and colleagues noted that practice patterns and early outcomes of histotripsy since the FDA clearance are “incompletely characterized.” The researchers studied these patterns and outcomes, using data collected between 2023 and 2026 from 972 patients who underwent histotripsy for liver tumor treatment.
Most patients received treatment at urban centers (88.2%). And 47.3% of patients reported having commercial insurance while 32.3% had Medicare.
The team reported that 69.8% of patients (n = 678) had histotripsy performed for metastatic disease while the remaining 30.2% (n = 294) received treatment for primary liver malignant tumors. The researchers wrote that this finding raises concern that histotripsy “is being used in patients with disease biology poorly suited to liver-directed therapy.”
Among metastatic tumors, the team reported colorectal cancer being the most frequent primary site (26.7%), followed by pancreatic cancer (12.4%). Among primary liver tumors, hepatocellular carcinoma (22.0%) and intrahepatic cholangiocarcinoma (8.2%) were most treated.
The team also found that “most” histotripsy procedures were performed in the outpatient setting, with 851 patients treated in a single session. And 859 patients (88.4%) were discharged the same day while 897 patients (92.3%) were discharged by the following day.
While procedural toxicity was, 30-day mortality was 11.1% and was overall similar among payer groups, the researchers found. Tsung said this finding “likely reflects the advanced cancer population receiving treatment rather than procedural complications.”
Finally, 30-day readmission and emergency department visit rates were 0.9% and 0.4%, respectively.
Tsung told AuntMinnie the study does not question histotripsy’s procedural safety but highlights the importance of defining evidence-based indications as adoption expands.
“Like any new cancer therapy, its greatest value will come from identifying the patients most likely to benefit through multidisciplinary evaluation and prospective comparative studies,” he said. “We hope these findings stimulate additional research that helps define the optimal role of histotripsy within liver-directed cancer care.”
The researchers are interested in defining best patient selection, understanding longer-term oncologic outcomes, and comparing histotripsy with established liver-directed therapies, Tsung said.
“Ultimately, our goal is to determine where histotripsy provides the greatest benefit within multidisciplinary cancer care,” he added.
Read the full study results here.
