Radiation Device Placed in Brain Cuts Tumor Recurrence, Boosts Survival
A postage stamp-sized implant eliminates a dangerous waiting period that has long worsened outcomes for cancer patients
- A new study found GammaTile, a radioactive wafer, nearly doubled survival rates for brain tumor patients.
- The study showed tumors grew back in 1% of GammaTile patients versus 12% of those receiving standard treatment.
- GammaTile avoids a two-month wait for external radiation after surgery, delivering direct radiation to the tumor site.
Brain tumors are one of the most devastating consequences of cancer’s spread—hard to treat and highly deadly. Scientists have found that using a radioactive implant precisely where a tumor was removed in the brain can help patients get their cancer treated more quickly and in many cases, live longer.
A new study showed that GammaTile, a radioactive wafer the size of a postage stamp, nearly doubled survival rates and nearly eliminated tumor regrowth in people who had it placed in the spot where brain tumors were surgically removed.
Between 100,000 and 200,000 Americans a year are diagnosed with cancer so advanced it has spread to the brain. Typically, patients get those tumors surgically removed and follow up with radiation therapy from a device outside of their body, rather than from within it.
The tiles are already cleared by the Food and Drug Administration. Until this study, which will be presented at the American Society of Clinical Oncology annual meeting this weekend, no large randomized trial had shown that they worked better than the traditional approach for these types of brain tumors.
In the new study, involving 230 people, nearly two-thirds of those given the tiles were alive two years later, compared with around a third of those who got standard radiation after surgery. Tumors grew back at the surgical site in just 1% of patients who got the implants, versus 12% of those who got the standard treatment.
“That survival difference is pretty astonishing,” said Dr. Molly Blau, a radiation oncologist at Fred Hutch Cancer Center in Seattle who wasn’t involved in the study. Blau said the results could fuel conversations with surgeons at her institution about investing in a GammaTile program.
After brain tumors are removed, a surgeon uses the tiles to line the walls of the empty cavities. The tiles can be cut to fit the contours of the space. They deliver a concentrated dose of radiation directly to the tissue most likely harboring remaining cancer cells. The tiles, made of collagen, become largely inert within weeks and are absorbed into the body. The process adds as little as two to three minutes to the operation.
The way these brain tumors are currently treated, patients have to wait up to two months after surgery to recover before returning for radiation, during which they are normally taken off chemotherapy, leaving cancer elsewhere in the body unchecked.
“That treatment gap is very anxiety provoking for patients and their families,” said Dr. Michael Garcia, chief medical officer of privately held GT Medical Technologies, the Arizona-based company that makes the tiles.
Stacy Dixon was able to avoid that wait. Weeks after she learned that her stage-four melanoma had spread to her brain and lungs, she traveled from her home in Tulsa, Okla., to Houston to become one of the first patients in the GammaTile clinical trial.
A surgeon from the University of Texas MD Anderson Cancer Center removed her brain tumor and lined the cavity with the implants in late November 2022.
Dixon, 47, described the brain surgery and recovery as remarkably easy. She returned home in time for Thanksgiving after a two-night stay in the hospital.
The safety of GammaTile treatment was comparable to standard radiation, according to the researchers, but the study found that cancer spread to the fluid-filled lining of the brain and spine in 9.7% of patients who received the tiles, compared with 3% in the other group. That gap wasn’t statistically significant, and Blau of Fred Hutch said that it wouldn’t necessarily deter her from offering the treatment.
Implementing a GammaTile program isn’t simple: It requires certification through state health authorities, specialized training for neurosurgeons and radiation physicists and buy-in across the oncology, radiology and surgery departments. The credentialing process alone can take up to six months, Blau said.
Researchers are also evaluating the tiles for patients with newly diagnosed glioblastoma—an aggressive brain cancer that doesn’t involve spreading from another organ—in a continuing study.