The Headline: Does tile brachytherapy reduce the risk of brain metastasis recurrence after resection compared with postop SRS?
The Study: Adjuvant SRS reduces local recurrence after brain metastasis resection. The ROADS trial was a randomized, phase 3 study that compared postoperative SRS with brachytherapy using cesium-131 tiles. It included 204 patients who were planned to have resection of a brain metastases, and up to 5 additional mets were allowed, which were treated with SRS. Those randomized to brachytherapy had cesium-131 tiles placed in the resection cavity immediately after resection. These tiles are made of bioresorbable collagen (which sticks to the moist cavity walls) embedded with 4 cesium-131 seeds. The walls of the cavity are lined with the tiles prior to closing. The nominal dose is about 60 Gy at 5mm depth from the cavity surface. After a median follow up of 12.9 months, the rate of surgical bed recurrence was significantly lower after brachytherapy (1% v 11.9%). The rate of leptomeningeal disease was numerically lower after SRS (3% v 9.7%), and the rate of radiation necrosis was similar (6.9% v 7.8%). While brachytherapy had superior surgical bed recurrence free survival, the surprising secondary finding was significant improvement in overall survival. Brachytherapy had nearly double the rate of overall survival at 24 months (61.7% v 35.7%). That’s a pretty hefty 30% improvement in overall survival from a 10% absolute improvement in local tumor recurrence for patients with metastatic disease.
TBL: In this randomized trial, cesium-131 tile brachytherapy following brain metastasis resection significantly reduced the primary outcome of surgical bed recurrence compared with postop SRS. | Weinberg, ASCO 2026
The Study: Adjuvant SRS reduces local recurrence after brain metastasis resection. The ROADS trial was a randomized, phase 3 study that compared postoperative SRS with brachytherapy using cesium-131 tiles. It included 204 patients who were planned to have resection of a brain metastases, and up to 5 additional mets were allowed, which were treated with SRS. Those randomized to brachytherapy had cesium-131 tiles placed in the resection cavity immediately after resection. These tiles are made of bioresorbable collagen (which sticks to the moist cavity walls) embedded with 4 cesium-131 seeds. The walls of the cavity are lined with the tiles prior to closing. The nominal dose is about 60 Gy at 5mm depth from the cavity surface. After a median follow up of 12.9 months, the rate of surgical bed recurrence was significantly lower after brachytherapy (1% v 11.9%). The rate of leptomeningeal disease was numerically lower after SRS (3% v 9.7%), and the rate of radiation necrosis was similar (6.9% v 7.8%). While brachytherapy had superior surgical bed recurrence free survival, the surprising secondary finding was significant improvement in overall survival. Brachytherapy had nearly double the rate of overall survival at 24 months (61.7% v 35.7%). That’s a pretty hefty 30% improvement in overall survival from a 10% absolute improvement in local tumor recurrence for patients with metastatic disease.
TBL: In this randomized trial, cesium-131 tile brachytherapy following brain metastasis resection significantly reduced the primary outcome of surgical bed recurrence compared with postop SRS. | Weinberg, ASCO 2026