May 7, 2026 By Kristin Emery 4 min read

A new approach to fighting brain tumors is showing promising results by targeting cancer cells with a tiny radiation-emitting implant.

The technique was first used in Southwestern Pennsylvania three years ago by neurosurgeons at Allegheny Health Network (AHN). Results of a 12-month followup are encouraging, showing the treatment helped prevent tumors from returning in 92% of patients and causing no major adverse reactions.

The procedure is called GammaTile and involves placing a small radiation-emitting implant at the time of tumor removal surgery. The implant delivers targeted radiation directly to the tumor bed, helping to fight its return while also minimizing exposure to healthy brain tissue.

“When I operate on the brain to remove a cancerous tumor, my primary responsibility is to preserve and/or improve neurologic function. In this way, I am often not able to remove a cancerous tumor with a margin of healthy brain tissue,” explains Dr. Matthew Shepard with the AHN Neuroscience Institute. He performed the first local GammaTile procedure in Western Pennsylvania in 2023 and has been involved in several studies examining its effectiveness for patients with brain metastases, gliomas and meningiomas.

“When brain tumors recur, they often grow back at the site of the initial surgery. Therefore, post-operative radiation is required,” Shepard says. “Unfortunately, recovering from surgery takes time. Often there is a balance between patient recovery and the growth trajectory of microscopic, residual tumors cells. In select, very aggressive cancers, some tumors can even grow so quickly that tumor progression can already be observed on brain MRIs within a few weeks after surgery. Thus, employing immediate, surgically targeted, radiation therapy mitigates the risk of early tumor recurrence and ensures that every patient has an opportunity to receive adjuvant radiation therapy.”

Since the radiation emitted from GammaTile is targeted just to the region of the brain that is at the highest risk of tumor regrowth, it limits exposure to surrounding healthy brain tissue, which is critical in preserving neurological function.

An estimated 1 million people in the U.S. are living with a brain tumor diagnosis with nearly 90,000 new cases of primary brain tumors diagnosed annually. About 30% of brain tumors are cancerous.

How does it work?

The postage stamp-sized GammaTile implant is similar to the radioactive seed brachytherapy treatment commonly used for prostate and breast cancers. The therapy is beneficial when brain tumors recur or when post-operative radiation or chemotherapy options are limited.

After tumor removal, neurosurgeons place one or more GammaTiles at the site to direct radiation to where the tumor is most likely to regrow and where leftover cancer cells might still be hiding. The radiation seeds are encased in a collagen wafer, which holds them in place until they become inert after two or three months. Then, surrounding brain tissue absorbs the collagen tile.

“This is a game-changer,” says Shepard. “GammaTiles target remaining tumor cells immediately once deployed. And because the tile keeps the cesium seeds securely in place while the radiation is released, the therapy occurs while the patient is out of the hospital as they go about their daily life.”

The targeted radiation means preserving more healthy brain tissue and reducing cognitive or motor skill complications and other side effects like hair loss.

Traditional treatment after brain tumor surgery calls for radiation or chemotherapy, which can last up to 30 visits over several weeks.

“Importantly, all of the patients in this study received radiation therapy as they were recovering from surgery,” says Shepard. “Almost one-third of patients treated with surgery for brain metastasis never receive post-operative radiation therapy, or if they do, the treatment is severely delayed.” Unfortunately, patients who do not receive that followup treatment have worse outcomes, so doctors see this technique addressing a common challenge in cancer care.

“Implantable radiation removes the treatment gap often required for surgical healing and ensures that every patient receives their full dose of radiation for the tumor that was removed.”