Key Takeaway:
- Implanted radiation tiles significantly reduced tumor recurrence after brain metastasis surgery compared with standard delayed radiation.
- Patients receiving the implanted therapy lived more than twice as long on the median while experiencing similar safety outcomes.
- Experts called the findings promising but urged caution, citing study limitations and the need for further analysis.
Patients with surgically removed brain metastases who received implanted tile-based radiation therapy immediately after surgery had lower recurrence rates and longer survival than those receiving standard delayed radiation, according to a phase III study presented at the 2026 ASCO Annual Meeting.
Implanted therapy reduces recurrence after surgery
Researchers reported that tile-based radiation therapy (TBRT), delivered during tumor removal surgery, outperformed standard postoperative stereotactic radiation therapy (SRT) in the phase III Radiation One and Done Study (ROADS).
The randomized trial enrolled 230 patients across 32 U.S. sites. A modified intention-to-treat analysis included 204 patients who underwent surgery and had follow-up data. Of those, 103 received TBRT during surgery, while 101 were assigned to receive SRT two to four weeks later.
TBRT uses implanted radiation tiles, collagen tiles containing cesium-131 radioactive seeds, placed inside the surgical cavity immediately after tumor removal, reflecting advances in brain cancer therapy. The implanted radiation tiles deliver focused radiation over about five weeks, eliminating the need to return later for postoperative radiation.
Only 1% of patients treated with TBRT experienced recurrence in the surgical cavity, compared with 11.9% of patients treated with SRT. Investigators also found that recurrence-free survival remained significantly longer in the TBRT group.
Trial shows longer survival with comparable safety
The study found median overall survival reached 42.5 months for patients receiving TBRT, compared with 17.6 months for those treated with SRT. Estimated two-year survival rates were 61.7% and 35.7%, respectively.
“We were quite surprised, and we’re extremely excited by this,” said Dr. Jeffrey S. Weinberg of The University of Texas MD Anderson Cancer Center, who presented the findings. He noted that the study was not designed primarily to measure overall survival and that additional analyses are underway to better understand the result.
Weinberg said using implanted radiation tiles during surgery also helps avoid treatment delays that commonly occur after brain surgery.
“Patients undergoing tumor resection currently face an inherent gap in care,” Weinberg said, explaining that postoperative radiation is often delayed for weeks, potentially affecting local tumor control and postponing systemic cancer treatment.
Researchers reported similar rates of functional status, quality of life, adverse events, radiation necrosis and leptomeningeal disease between the two treatment groups, suggesting the implanted radiation tiles did not increase toxicity.
Experts urge caution despite encouraging findings
Independent experts described the results as promising but said additional evaluation is needed before the approach becomes routine.
“If this proof of concept holds, [TBRT] would largely supplant cavity radiosurgery for this indication,” said Dr. David Schiff of the University of Virginia School of Medicine, an ASCO expert in central nervous system tumors.
Schiff also cautioned that about 20% of randomized patients were excluded from the primary outcomes analysis after randomization, a factor that can influence study results. He added that the large survival improvement was unexpected because most patients with brain metastases die from cancer outside the brain rather than progression within the central nervous system.
Researchers acknowledged that the open-label design represents a limitation but said blinding is not practical for surgical radiation studies. Ongoing analyses are examining whether TBRT also improves cognition, memory and attention, while another clinical trial is evaluating the technology in patients with glioblastoma.
The ROADS study was funded by GT Medical Technologies, with findings presented at the 2026 ASCO Annual Meeting. Investigators disclosed financial relationships with the company and other organizations.
