Tile-Based Radiation Therapy Reduces Recurrence Risk After Brain Metastasis Surgery

Brain metastases can occur in patients with advanced solid tumors and may affect treatment options and prognosis. For patients with larger or symptomatic lesions requiring surgery, microscopic tumor cells left in the surgical cavity can cause recurrence in 50%–60% of cases without radiation. Standard postoperative stereotactic radiation therapy must be delivered on schedule, but delays and missed treatment can compromise care. New findings demonstrate that tile-based radiation therapy may improve local tumor control after surgery.

Researchers at the University of Texas MD Anderson Cancer Center led the multicenter ROADS trial evaluating GammaTile cesium-131 collagen tile-based radiation therapy, or TBRT. The approach uses a Food and Drug Administration (FDA)-cleared low-dose brachytherapy device developed by GT Medical Technologies Inc. The postage-stamp-sized collagen tiles contain evenly spaced cesium-131 seeds and are placed along the surgical cavity during brain surgery.

The tiles deliver low-dose therapeutic radiation over several weeks to the cavity surface, where remaining microscopic tumor cells are most likely to be located. The source material states that brachytherapy has rapid dose fall-off, limiting radiation exposure to healthy brain tissue. The ROADS trial compared surgery plus TBRT with surgery plus standard postoperative stereotactic radiation therapy, or SRT, in patients with newly diagnosed brain metastases who needed surgery.

ROADS was the first randomized controlled Phase III trial comparing GammaTile TBRT with standard-of-care postoperative SRT. After one year, recurrence at the surgical site was 1.3% in the TBRT group compared with 15.4% in the SRT group. Median overall survival was 42.5 months with TBRT and 17.6 months with standard SRT, a key secondary endpoint of the trial.

Serious treatment-related side effects did not differ between the two groups. Radiation necrosis rates were nearly identical. Patients receiving TBRT completed cranial radiation faster, most in one day, compared with a median of 32 days for patients who needed postoperative SRT.

The study was published in the Journal of Clinical Oncology on September 28, 2026, and presented at the 2026 American Society of Clinical Oncology Annual Meeting. The investigators stated that the results could reduce logistical challenges associated with SRT and improve disease control in the brain. Future work may evaluate how broadly TBRT affects metastasis care and whether it has potential in other tumor types.

“Implanting the radioactive tiles at the time of surgery guarantees that patients receive their treatment immediately, along with focal dose escalation, thereby having meaningful impact on local tumor control. From a patient standpoint, we're showing that there's almost four times the length of local control and an increase in overall survival. It's not just a little difference. It's a massive difference,” said Jeffrey Weinberg, M.D., professor of neurosurgery.

Related Links
GT Medical Technologies 
UT MD Anderson Cancer Center