Tile-Based Radiation Improves Surgical Bed Recurrence in Brain Metastases

Resection combined with cesium-131 collagen tile-based radiation therapy (TBRT; GammaTile) significantly improved time to surgical bed recurrence (SBR) and surgical bed recurrence-free survival (SB-RFS) compared with resection followed by stereotactic radiation therapy (SRT) in patients with newly diagnosed operable brain metastases, according to results from the randomized, open-label, non-inferiority phase 3 ROADS trial (NCT04365374) published as a Rapid Communication in the Journal of Clinical Oncology.¹ TBRT met both co-primary end points, SBR and SB-RFS, demonstrating both non-inferiority and superiority over SRT.

“The Rapid Communication publication in the Journal of Clinical Oncology reflects how significant these findings are for patients with newly diagnosed brain metastases,” stated Jeffrey Weinberg, MD, professor of neurosurgery at The University of Texas MD Anderson Cancer Center, co-lead investigator of the ROADS trial, and first author on the publication, in a press release on the findings.² “Standard-of-care treatment for this disease has always focused on controlling the tumor in the brain so patients can get back to fighting their primary cancer, and TBRT (GammaTile) does that more effectively than existing treatment options. By initiating radiation at the moment of surgery, TBRT closes the gap between resection and radiation treatment for the operable tumor entirely, and this randomized evidence supports it as a new standard-of-care option that gives patients that certainty from day one.”

What were the efficacy results from the ROADS trial?

In the modified intent-to-treat (mITT) population of 204 patients, the median time to SBR was not reached (NR) with resection plus TBRT vs 17.4 months with resection plus SRT (HR, 0.06; 95% CI, 0.01-0.46; P = .0070). SB-RFS was also improved with resection plus TBRT, with a median of NR vs 10.9 months with resection plus SRT (HR, 0.48; 95% CI, 0.30-0.76; P = .0021). At 12 months, the cumulative incidence of SBR was 1.3% (95% CI, 0.1%-6.1%) in the TBRT group vs 15.4% (95% CI, 7.1%-26.6%) in the SRT group (subdistribution HR, 0.07; 95% CI, 0.01-0.56; P = .012). The developer, GT Medical Technologies, described in the press release this rate as the lowest tumor recurrence rate reported in a published randomized controlled trial of newly diagnosed operable brain metastases.

The median overall survival (OS) was 42.5 months (95% CI, 20.8-not estimable [NE]) with TBRT vs 17.6 months (95% CI, 10.9-25.5) with SRT (HR, 0.59; 95% CI, 0.37-0.96; P = .032). In an exploratory composite end point combining SBR and radiation necrosis (RN), resection plus TBRT was associated with a longer time to the combined event (HR, 0.28; 95% CI, 0.12-0.66; P = .004).

What safety and quality-of-life findings were reported?

Adverse events (AEs) did not significantly differ between trial arms: 83 patients (79.0%; 95% CI, 70.0%-86.4%) receiving resection plus TBRT experienced any AE vs 67 patients (80.7%; 95% CI, 70.6%-88.6%) receiving resection plus SRT. Grade 3 or higher treatment-related AEs occurred in 20.0% of patients in the TBRT group vs 21.7% in the SRT group.

At 12 months, the cumulative incidence of RN was 5.3% (95% CI, 1.7%-12.2%) with TBRT vs 5.7% (95% CI, 1.8%-13.0%) with SRT (HR, 0.85; 95% CI, 0.31-2.36; P = .76). The median duration of craniotomy hospitalization was 3.0 days in the TBRT group vs 4.0 days in the SRT group (HR, 1.09; 95% CI, 0.82-1.45; P = .56).

The investigators reported no differences between arms in quality of life (using the FACT-Br instrument), functional status (using Karnofsky Performance Status and Barthel Index of Activities of Daily Living), or neurocognitive function.

How was the ROADS trial designed?

Across 32 US centers, 230 patients were randomly assigned 1:1 before surgery to receive either resection plus TBRT or resection plus SRT using covariate-adaptive minimization, stratified by age, duration of extracranial disease control, number of brain metastases, primary tumor histology, maximum index metastasis diameter, and prior or current immunotherapy. The mITT population consisted of 103 patients in the TBRT group and 101 in the SRT group.

Eligible patients had 1 surgical brain metastasis measuring 2.0 to 7.0 cm, with up to 5 additional brain metastases measuring 4.0 cm or smaller that did not require resection and that were treated with SRT after surgery. For resection plus TBRT, the resection cavity was lined with tiles containing cesium-131 sources (apparent activity, 5.5 mCi per source) immediately following resection. For resection plus SRT, cavity SRT was volume-dependent and planned for 1 fraction (17-20 Gy), 3 fractions (27 Gy), or 5 fractions (30 Gy), beginning 21(±7) days after surgery.

Because some patients in the SRT group did not receive their assigned radiation, the study authors noted that 17.8% of patients randomized to resection plus SRT did not receive their prescribed post-operative SRT, which they said is consistent with previously published rates of 20% to 27% for post-operative SRT non-completion.^2,3 To address this, the authors also conducted a per-protocol analysis limited to patients in each arm who received their assigned treatment; TBRT's superiority in both co-primary end points persisted in that analysis.

Thomas H. Beckham, MD, PhD, associate professor of CNS radiation oncology at MD Anderson and corresponding author on the publication, said, “The trial was designed to compare resection and TBRT [vs] resection and post-operative SRT, a pathway in which some patients do not ultimately receive their planned radiation. But even when we analyzed only those patients in each arm who did receive their assigned radiation, TBRT remained superior on both co-primary end points. That tells us this advantage isn't explained solely by guaranteed radiation delivery.”

In the manuscript's conclusion, the study authors stated that resection plus TBRT should be considered a standard-of-care option for patients with newly diagnosed brain metastases requiring resection, citing the trial's randomized design, longer median follow-up than the studies that established post-operative SRT as standard of care, superiority on both co-primary end points, and the absence of increased RN, neurocognitive decline, or quality-of-life deterioration.

References

1. Weinberg JS, Imber BS, DiNapoli V, et al. Surgery and tile-based radiation therapy versus surgery and stereotactic radiation for newly diagnosed brain metastases (ROADS): a randomized, open-label, phase 3 trial. J Clin Oncol. Published online September 28, 2026. doi:10.1200/JCO-26-01894
2. Publication of ROADS phase 3 clinical trial data in Journal of Clinical Oncology recommends GammaTile® as a new standard-of-care option for newly diagnosed operable brain metastases1. News release. GT Medical Technologies, Inc. September 29, 2026. Accessed September 30, 2026. https://tinyurl.com/2chza29p
3. Yeboa DN, Li J, Lin R, et al. Therapy, safety, and logistics of preoperative vs postoperative stereotactic radiation therapy: a preliminary analysis of a randomized clinical trial. JAMA Oncol. 2025;11(8):890-899. doi:10.1001/jamaoncol.2025.1770