Novel radiation therapy device could be game changer for glioblastoma treatment
Experts have developed a novel radiation therapy device they say can be inserted intraoperatively during tumor removal surgery to help slow regrowth in patients with glioblastoma.
Standard treatment for these fast-growing brain tumors typically involves surgical resection followed by radiation and chemotherapy. However, these treatments are generally delayed for up to six weeks after surgery to allow the brain and surgical site to heal. During that interval, residual cancer cells can continue to grow, as is the case with glioblastoma—one of the most aggressive forms of brain cancer.
New research from a 15-center trial presented at the 2026 American Society of Clinical Oncology's annual meeting suggests that a radiation therapy device could help address the gap in between surgery and initiating additional treatments. The trial evaluated a device referred to as GammaTile, which contains cesium-131 radioactive seeds that can be placed directly into the surgical cavity after tumor removal.
The device delivers radiation over a short distance, concentrating treatment around the surgical cavity rather than exposing larger areas of the brain. Experts involved in its development suggest the localized approach allows radiation to begin immediately without interfering with wound healing and can deliver doses two to four times higher than those considered safe with conventional external beam radiation therapy.
So far, it has been tested on 67 patients who underwent surgery and GammaTile placement followed by a shortened course of external beam radiation and chemotherapy. The results of those cases suggest that the treatment is feasible and does not produce more serious adverse effects than what would be expected with standard treatment. Early tumor regrowth was observed in just 6% of patients, which is substantially lower than the 50% to 70% rate cited by prior research as occurring in patients after surgery but before additional treatments.
GammaTile was developed by Rhode Island-based GT Medical Technologies, which specializes in devices targeting brain tumors. The Phase 1 GESTALT clinical trial testing the device is being led by Clark Chen, MD, PhD, professor and director of the Brain Tumor Program at Brown University Health; Chen believes targeting the window of time between tumor removal and the initiation of additional treatments could give patients a significant advantage.
"These results suggest that immediate radiation treatment at the time of surgery may address one of the most significant challenges in glioblastoma care," Chen said in his presentation. "By treating residual cancer cells during the recovery period, we may be able to reduce early tumor regrowth while maintaining the safety of standard treatment."
"GammaTile was built to close the gap in glioblastoma care created by the wait for traditional external beam radiation to begin after surgery," Michael Garcia, MD, MS, chief medical officer of GT Medical Technologies, said in a news release on the findings. "These results show what's possible when we stop giving residual cancer cells time to regrow between surgery and radiation."
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In addition to her background in journalism, Hannah also has patient-facing experience in clinical settings, having spent more than 12 years working as a registered rad tech. She began covering the medical imaging industry for Innovate Healthcare in 2021.