SADA-17 SURVIVAL AND LOCAL CONTROL AFTER RESECTION AND GAMMATILE BRACHYTHERAPY FOR NEWLY DIAGNOSED BRAIN METASTASES: A PROSPECTIVE REGISTRY ANALYSIS
TL;DR
In this prospective registry, resection followed by GammaTile brachytherapy achieved excellent local control, and manageable toxicity in newly diagnosed BM, supporting that GammaTile brachytherapy is a promising strategy for large or symptomatic BM.
Abstract
Abstract Background Surgical resection is a standard treatment for large and/or symptomatic newly diagnosed brain metastases (BM). GammaTile brachytherapy delivers immediate intracavitary radiation at surgery and may reduce delay in postoperative treatment. Despite increased usage and adoption, prospective data remain limited. Methods We analyzed an ongoing multicenter, prospective Phase IV registry (NCT0442738) of patients undergoing BM resection followed by GammaTile brachytherapy. Primary outcome was overall survival (OS); secondary outcomes were local control (LC) and distant brain failure (DBF). Time-to-event endpoints were estimated by Kaplan-Meier methods, and Cox models were used to identify predictors of outcome. Results 89 patients with 95 lesions were treated with resection and brachytherapy. Median age was 64 years (range: 28–81), 56.2% were male, and median KPS score was 80 (range: 30-100). Primary histology included predominantly lung (36%), followed by melanoma (12.4%) and breast (11.2%). The median BM diameter was 3.2cm (range 1.1-5.5cm) and most lesions were supratentorial (84.2%). Gross total resection was achieved in 86.3% of patients. At analysis, 48.8% of patients had died. Median OS was 8.6 months (95% CI: 6.0-20.1 months), with 6- and 12-month OS rates of 59.4% and 45.1%, respectively. Local failure occurred in 7.9% patients. The 6- and 12-month LC rates were 96.9% and 92.5%, respectively. DBF occurred in 19% of patients, with 6- and 12-month DBF-free rates of 82.2% and 68.4%. Melanoma histology was associated with worse DBF on multivariable analysis (HR: 5.31, p=0.043). Seizures occurred in 6.7% of patients, while intracerebral hemorrhage and cerebral edema were observed in 1.1% and 2.2% patients, respectively. Conclusions In this prospective registry, resection followed by GammaTile brachytherapy achieved excellent local control, and manageable toxicity in newly diagnosed BM. These findings support that GammaTile brachytherapy is a promising strategy for large or symptomatic BM. Future work to better define patient selection is planned.