Early Experience and Perioperative Risk of GammaTile® for Upfront Brain Metastases: Report from a Multicenter Study

Introduction: GammaTile (GT Medical Technologies, USA), a form of brachytherapy utilizing cesium-131 seeds embedded in a collagen carrier, has gained popularity for treatment of recurrent intracranial lesions. Indications have recently broadened to include upfront metastases. This study reports early experience utilizing GammaTile in upfront brain metastases with focus on clinical applications and perioperative safety profile.

Methods: The GammaTile Registry was assessed for all patients receiving GammaTile for upfront metastasis from August 2021 to August 2023. Data regarding patient demographics, procedure details, and adverse events was extracted and analyzed.

Results: Twenty-eight patients, mean age 62.1 years, with 30 treated metastases were reported from 6 institutions. Most common primary malignancies were lung (42.9%), melanoma (14.3%), breast (10.7%), and renal (10.7%). Patients had 2.8 metastases on average (range 1-15) at time of surgery; however, most patients had single metastasis (60.7%). Average maximum diameter of treated metastases was 3.4 cm (range 1.5-4.7). Gross total resection was achieved for 96.7%. On average, 4.6 tiles (range 1-10) were used per tumor. The cohort had an average follow-up of 4.4 months with 6 reported adverse events (21.4%), not directly attributable to GammaTile and including only one grade ≥3. In the immediate postoperative period, two patients reported pain or headache, and one reported facial edema. One patient developed seizures on postoperative day 8 requiring medication. At one-month follow-up, there was one superficial wound infection, in a previously colonized patient, requiring surgical intervention without explantation of tiles. At three-month follow-up, one patient reported facial pain not requiring treatment. There were no symptomatic hematomas or mortalities.

Conclusion : GammaTile demonstrates a favorable safety profile in upfront brain metastases with a 3.6% rate of serious adverse events (grade ≥3). Data collection is ongoing, and further follow-up is required to evaluate outcomes.