Clinical Trials of Focused Ultrasound for Brain Tumors.

Background: It is unclear as to where we stand with respect to utilizing emerging focused ultrasound (FUS) technology in the setting of brain tumor treatment in pediatric patients, such as malignant diffuse intrinsic pontine glioma, and various adult counterparts. Correspondingly, the aim of this study was to present a contemporary summary of all pertinent clinical trials to date.

Methods: The ClinicalTrials.gov database was reviewed in January 2025 for all possible clinical trials involving FUS in the management of brain tumors. These were then screened against selection criteria to identify pertinent clinical trials.

Results: A total of 30 clinical trials were identified. The majority were focused on adult patients (24/30, 80%), with the most common tumor type being glioblastoma (GBM) (14/30, 47%). There were also trials focused on pediatric patients only (5/30, 17%), as well as diffuse intrinsic pontine glioma (DIPG) (5/30, 17%). The most prevalent primary outcome of interest was safety (26/30, 87%). The majority of trials were active, either recruiting currently (12/30, 40%), or active but not recruiting currently (3/30, 10%). North America (22/30, 73%) was the most common location for the primary coordinating institution, and the median number of institutions per trial was one. The median expected start year for all trials was 2021, and the completion year was 2024. To date, there have been no results (interim or final) formally reported, although preliminary reports in the literature indicate this to be a safe procedure. Anecdotal trends suggest later trials target the blood-brain barrier more, involve more pediatric patients, and are more based in the United States.

Conclusion: There exists a number of early-stage clinical trials investigating FUS to treat a variety of brain tumors in pediatric patients, as well as adult patients, with a significant clinical potential to improve outcomes. To date, no official results have been published, however anecdotal evidence is promising, and a number of results are expected soon.