Key Points
- The Foundation recently hosted a workshop on the use of focused ultrasound to treat diffuse intrinsic pontine gliomas (DIPG).
- The presentations, discussions, and a roadmap for future research will be summarized in a white paper.
On May 13–14, 2025, the Foundation hosted an in-person, 1.5-day workshop on focused ultrasound for diffuse intrinsic pontine glioma (DIPG). The event took place in San Diego, California, as a satellite meeting leading up to the 8th Biennial Pediatric Neuro-Oncology Conference. The first Foundation workshop on this topic was held in October 2021.
This year’s workshop convened 20 neuro-oncologists, neurosurgeons, neuro-radiologists, focused ultrasound experts, and representatives from industry, the Foundation, and the US Food and Drug Administration. Attendees heard presentations about the latest preclinical research and clinical trial updates and then discussed burning questions for moving the field forward. A few additional participants joined virtually via Zoom.
Focused ultrasound clinical trials have thus far sought to use either sonodynamic therapy (SDT) or blood-brain barrier (BBB) opening with the delivery of chemotherapy in patients with DIPG.
On the first day of the workshop, attendees discussed BBB opening procedures for the delivery of chemotherapies and other drugs. Liquid biopsy, immunotherapies, and SDT were explored on day two. Invited speakers provided insights on the development of therapeutic microbubbles for BBB opening, results from ongoing clinical trials, preclinical research advances, and how liquid biopsy is currently being used to diagnose DIPG and monitor disease progression and treatment response.
“We are now building on progress made over the past 3.5 years since our 2021 DIPG Workshop,” said the Foundation’s Associate Director of Research and Education, Lauren Powlovich, MD, MBA. “The Foundation has a deep interest and investment in continuing to advance the field in this area, to facilitate information sharing among researchers, and to make headway in creating more treatment options for families that are devastated with DIPG diagnoses.”
The group addressed the following burning questions:
Session 1
1. What volume of BBB opening is needed?
2. Are focused ultrasound parameters optimized for BBB opening of the pons? If not, how do we optimize?
3. What has been learned about the timing of drug vs. focused ultrasound, and is this optimal and consistent?
4. How can we measure and validate drug delivery and response post–focused ultrasound?
5. What are the technical barriers to effective BBB opening in the pons?
6. How can results be harmonized for optimal interpretation?
7. What preclinical evidence exists to point us to the next drug to be combined with focused ultrasound? How can this be balanced with drug access vs. ideal drug candidates?
8. What strategies can be employed for increased enrollment in clinical studies?
9. Should expansion to additional patient populations (i.e. different tumor types) be explored?
Session 2
Panel 1: Liquid Biopsy
1. What biomarkers or “windows of response” should be monitored via liquid biopsy?
2. What is the best methodology for liquid biopsy?
3. Should CSF, blood, or both be collected and analyzed?
Panel 2: Immunotherapy and SDT
1. How can we optimize immunotherapy and SDT clinical trials (consider patient selection/stage subtypes, focused ultrasound parameters, drug selection, and timing of drug)?
2. Is a combination of chemotherapy + immunotherapy + BBB opening possible?
A synopsis of the presentations and panel discussions from the workshop will be made available in a forthcoming white paper.
Workshop Resources
The following content was provided to attendees ahead of the meeting:
Can Focused Ultrasound Overcome the Failure of Chemotherapy in Treating Pediatric Diffuse Intrinsic Pontine Glioma Due to a Blood–Brain Barrier Obstacle? By Filieri et al. 2025
Current Immunotherapeutic Approaches to Diffuse Intrinsic Pontine Glioma by Lin, Smith, and Rutka 2024
Microbubble-Enhanced Focused Ultrasound for Infiltrating Gliomas by Seas et al. 2024
MR-Guided Focused Ultrasound in Pediatric Neurosurgery: Current Insights, Technical Challenges, and Lessons Learned from 45 Treatments at Children’s National Hospital by Keating et al. 2024
First-in-Human Sonodynamic Therapy with ALA for Pediatric Diffuse Intrinsic Pontine Glioma: A Phase 1/2 Study Using Low-Intensity Focused Ultrasound by Syed et al. 2023
Comparison of Sonication Patterns and Microbubble Administration Strategies for Focused Ultrasound–Mediated Large-Volume Drug Delivery by Gong et al.