Immediate radiation with GammaTile during glioblastoma surgery versus standard timing

Randomized Study of Resection and GammaTile® Followed by Concurrent External Beam Radiation Therapy (EBRT) and Temozolomide (TMZ) and Adjuvant TMZ Versus Standard of Care in Newly Diagnosed Glioblastoma (GBM)

Phase 3 Interventional GT Medical Technologies, Inc. · NCT07195591

This trial tests whether placing GammaTile at the time of surgery to start radiation right away, combined with temozolomide, helps adults with newly diagnosed glioblastoma compared with the usual delayed external beam radiation schedule.

Quick facts

PhasePhase 3
Study typeInterventional
Enrollment766 (estimated)
Ages18 Years and up
SexAll
SponsorGT Medical Technologies, Inc. Industry-sponsored
Locations4 sites (Scottsdale, Arizona and 3 other locations)
Trial IDNCT07195591 on ClinicalTrials.gov

What this trial studies

This is a phase 3, randomized, open-label, multi-site superiority trial that randomizes adults with newly diagnosed glioblastoma in a 1:2 ratio between standard resection with postoperative external beam radiation and resection with intraoperative GammaTile implantation. In Arm A participants undergo resection followed by EBRT (30 fractions) with concurrent temozolomide (75 mg/m2/day for 6 weeks), while Arm B participants receive resection plus GammaTile implantation followed by a shortened course of EBRT (20 fractions) with the same concurrent temozolomide dose for 4 weeks. All participants then receive adjuvant temozolomide (150–200 mg/m2/day) in six 28-day cycles starting about 28 days after completion of EBRT; patients with IDH-mutant tumors will be followed for safety and quality of life but excluded from the primary comparative analyses. Outcomes will compare survival, local control, and safety between the immediate intraoperative radiation approach and standard timing.

Who should consider this trial

Good fit: Adults (≥18) with radiographic suspicion of newly diagnosed glioblastoma who are medically and surgically eligible for resection, have a KPS ≥70, and can receive standard temozolomide are the intended candidates.

Not a fit: Patients with multifocal enhancing tumors that cannot be encompassed in one operative field, those with contraindications to temozolomide or MRI/gadolinium/CT, and those ultimately found to have IDH-mutant glioma (for the primary efficacy analysis) may not benefit from this comparison.

Why it matters

Potential benefit: If successful, this approach could start radiation sooner at the tumor site, potentially improving local tumor control and survival while limiting radiation exposure to healthy brain.

How similar studies have performed: Smaller nonrandomized and early-phase reports of GammaTile in recurrent and newly diagnosed brain tumors have shown promising local control, but randomized Phase 3 evidence has been limited until now.

Eligibility criteria

Show full inclusion / exclusion criteria
Major Criteria Includes the Following:

Inclusion Criteria

* Patients must be ≥18 years of age.
* Have radiographic suspicion of newly diagnosed glioblastoma (GBM).

  o If final pathology reports IDH mutant glioma, then the patients found to have an IDH mutation will be followed for safety and QoL measures but will not be included in the primary and secondary comparative survival and efficacy analyses.
* Are medically and surgically appropriate for resection.
* Have an estimated Karnofsky Performance Scale (KPS) score of ≥70.
* Are able to receive standard of care treatment.

Exclusion Criteria

* A previous biopsy diagnosis other than IDH wild-type GBM.
* Have contraindications to TMZ, magnetic resonance imaging, gadolinium, or non-contrast computed tomography.
* Have multi-focal enhancing tumors that cannot be encompassed in one operative field.

Where this trial is running

Scottsdale, Arizona and 3 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions GlioblastomaNewly DiagnosedGammaTileExternal Beam Radiation TherapyTemozolomideBrainTumorBrachytherapy
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.