First-Year Results Show Promise for Histotripsy in Treating Liver Tumors

One year after receiving FDA clearance, histotripsy—a noninvasive, nonthermal focused ultrasound technique— is showing encouraging results in the treatment of liver tumors, according to new data from an academic medical center.

Histotripsy mechanically destroys tumors using focused ultrasound waves, offering a non-ionizing alternative to traditional ablation methods. Researchers report what they believe is the first evidence of medium-term oncologic efficacy for the technology, particularly in achieving local tumor control.

Between December 20, 2023, and November 30, 2024, physicians treated 109 liver lesions in 71 patients. Most cases were advanced: 66% were treated with palliative intent, while 9% were treated with curative intent. Overall, 75% of procedures aimed for complete tumor ablation.

Among patients treated with curative intent, outcomes were especially notable. Seventy percent (7 of 10 patients) had nonviable tumors on imaging just one day after treatment. All of these patients maintained tumor nonviability at both 30- and 90-day follow-ups. In total, 70% achieved no evidence of disease after a single treatment. Of the three patients with persistent disease, two underwent repeat histotripsy and were subsequently converted to no radiologic evidence of disease, raising the overall disease-free rate at 90 days to 90%.

Tumor control was strongest when lesion targeting was accurate. Sixty lesions were nonviable on postoperative day 1, and all remained nonviable at 30 days. Among the 23 lesions with 90-day imaging available, 100% maintained tumor nonviability.

However, targeting challenges were noted. Of 82 lesions intended for complete ablation, 74% demonstrated nonviability on day 1 imaging, highlighting room for technical improvement. Researchers observed a slight, though not statistically significant, improvement in targeting as clinicians gained experience.

Importantly, histotripsy demonstrated a strong safety profile. Complications were rare, with only one case (1%) classified as Clavien grade 3 or higher.

Investigators conclude that histotripsy “is a safe procedure that is starting to demonstrate promise in effectively controlling local tumors when lesions are accurately targeted.” They emphasize that continued technical refinement and provider experience will likely improve outcomes, mirroring the early evolution of other tumor ablation techniques.