Canadian doctors perform world-first delivery of treatment for inoperable brain tumour in kid using ultrasound

Canadian physicians have successfully used an MRI-guided ultrasound to deliver chemotherapy to an inoperable brain tumour in a child – a world-first for this type of technology.

It’s the start of a groundbreaking clinical trial at Sunnybrook Health Sciences Centre and Toronto’s Hospital for Sick Children that researchers and doctors are hoping could open the door to better treat terminal paediatric tumours.

The procedure was performed on a patient with diffuse intrinsic pontine glioma (DIPG), which is the most common form of brain tumour in children under the age of 15, SickKids said.

“DIPG is a devastating pediatric brain tumour which is inoperable due to its location in the brainstem,” Dr. Nir Lipsman, study co-principal investigator and director of Sunnybrook’s Harquail Centre for Neuromodulation, said in a press release.

“Focused ultrasound is an innovative and non-invasive approach to more effectively deliver chemotherapy directly to the tumour. Our hope is that this continued research will bring us closer to enhancing treatments to help change the course of the disease.”

DIPG affects the brainstem, specifically the area that regulates involuntary actions such as swallowing, heart rate and even breathing. Although radiation treatment can buy time, DIPG is considered a terminal diagnosis.

That’s something researchers are hoping to challenge with this clinical trial.

Their new method of treatment delivery works by using low-intensity ultrasound to tackle the blood-brain barrier.

The blood-brain barrier is a protective network of closely packed cells situated between the capillaries in the brain and the brain’s other soft tissues. This network of cells shields the brain from harmful substances and toxins.

But when there is something going wrong inside the brain, such as a tumour, the blood-brain barrier becomes a roadblock for physicians hoping to deliver treatment to the affected areas.

That’s where ultrasound comes in.

Using the power of soundwaves, researchers have been able to force open a temporary door in this wall around the brain in order to let treatment through that would’ve otherwise been unable to penetrate the barrier.

This new clinical trial, which includes 10 patients between 5-18 years old who have DIPG, is seeking to establish the safety and feasibility of this procedure in children.

It builds on previous research conducted by Sunnybrook. In 2015, researchers successfully used focused ultrasound for the first time to deliver chemotherapy to the brain tumour of an adult patient.

So how does the procedure actually work?

Patients lie in an MRI machine, wearing a specially designed helmet that delivers sound waves into precise areas of the brain without the need for surgery, as physicians monitor their progress using MRI.

Microscopic bubbles smaller than red blood cells are injected intravenously into the bloodstream. The focused sound waves cause these microscopic bubbles to vibrate, expanding the space between the cells that make up the blood-brain barrier and opening up temporary holes through which doses of chemotherapy can be delivered directly into the brain.

This gap in the blood-brain barrier is open only temporarily – around 12 hours after treatment, the blood-brain barrier will have re-sealed itself.

If this clinical trial is successful, it could mean hope for children facing a terminal diagnosis of DIPG.

“Current treatment for DIPG is limited to radiation, which can slow progression of the tumour for a period of time, but does not have longer-term effects,” Dr. James Rutka, study co-principal investigator and director of the Arthur and Sonia Labatt Brain Tumour Research Centre, said in the release. “Focused ultrasound technology is a promising drug-delivery strategy that is helping us penetrate the blood-brain barrier in a novel way. Conducting this trial will help us build new and innovative treatment pathways for children with DIPG.”