Electric fields show promise against aggressive glioblastoma in animal studies

A neurosurgeon treating Parkinson's disease patients with implanted electrodes had a thought that would take him down an unexpected path. If tiny electrical signals could calm the tremors of a degenerative neurological disorder, Matthew Hebb wondered, might they also disrupt the growth of brain cancer? That question, posed more than a decade ago, has now yielded the first promising results in living animals.

Hebb, a neurosurgery professor at Western University's Schulich School of Medicine & Dentistry, began with tumor tissue removed during surgery. He implanted electrodes into the samples and applied electrical stimulation. The cancer cells responded. That observation—unexpected enough to warrant investigation—launched a research program that would eventually involve physicists, biomedical engineers, and mathematicians working in concert to develop what is now called Intratumoral Modulation Therapy, or IMT.

Glioblastoma is among the cruelest cancers. It begins in the brain or its surrounding tissues and progresses with brutal speed. Even when patients receive the full arsenal of modern medicine—surgery to remove the tumor, radiation to kill remaining cells, chemotherapy to poison what escapes—the median survival stretches barely past one year. The cancer's cells divide so rapidly that recurrence is nearly inevitable, often sprouting near the original surgical site. Conventional treatments, for all their toxicity and burden, cannot stop it reliably enough.

IMT takes a fundamentally different approach. Rather than attempting to burn or destroy the tumor with acute electrical damage, the treatment delivers chronic, low-amplitude electric fields that interfere with the mechanics of cell division itself. When the fields are applied, cancer cells stall in their division process—they cannot complete the biological choreography required to split into daughter cells. The exact mechanisms remain under investigation, but the effect has been consistent across years of study.

The latest work, published in Neuro-Oncology Advances, marks a significant advance. A team led by Hebb, including physicist Eugene Wong, medical biophysicist Terry Peters, anatomist Susanne Schmid, and postdoctoral researcher Erin Iredale, tested the system in rats using multiple electrodes implanted around the tumor. By shifting the timing of electrical signals from each electrode, they created a dynamic field that rotates over time—essentially triangulating the tumor to ensure complete coverage and eliminate "cold spots" where cancer cells might escape treatment. The results were striking: an eightfold reduction in tumor growth measured by bioluminescence and a fivefold reduction in tumor volume measured by MRI after just seven days. Critically, the treatment produced no neurological damage or adverse effects in the surrounding brain tissue.

The challenge of precision—knowing exactly where to place electrodes and how much stimulation to deliver—has occupied much of Iredale's work since she joined the project as an undergraduate student in 2016. She developed a treatment-planning system that uses computational modeling to predict how electric fields will distribute through the brain tissue and to optimize electrode placement for individual patients. A physician could eventually input a patient's MRI scan, and the system would calculate the precise electrode positions and stimulation parameters needed for that person's tumor. The system currently relies on traditional computational methods, though artificial intelligence could be incorporated later.

The research trajectory is clear: from cancer cells in a dish to animal models to, eventually, human patients. Iredale and her colleagues are already building a prototype with an eye toward a first-in-human clinical trial. She estimates that within five to ten years, IMT could enter initial testing in glioblastoma patients—and if those trials succeed, it could become a standard option in the treatment arsenal for a disease that has resisted nearly every approach medicine has thrown at it. For patients facing a diagnosis that currently offers little hope, that possibility represents something worth watching.