Multicenter phase 3 trial of tile-based radiotherapy versus stereotactic radiation after surgery for newly diagnosed brain metastases

Postoperative stereotactic radiation (SRT) is the standard-of-care for resected brain metastases. Implantation of cesium-131 collagen tiles (tile-based radiation therapy; TBRT) initiates focal radiation immediately after resection. The phase 3 ROADS trial, at 32 centers in the US compared resection followed by TBRT (R+TBRT) versus resection plus SRT (R+SRT) among patiens with newly diagnosed brain metastasis indicated for surgical resection. Patients were preoperatively randomized 1:1 to R+TBRT of R+SRT. Any non-resected brain metastases received SRT postoperatively. Coprimary outcomes were time-to-surgical bed recurrence (SBR) and surgical bed recurrence-free survival (SB-RFS). A total of 230 patients were randomized, 204 of whom (103 R+TBRT; 101 R+SRT) comprised the mITT population. Median follow-up was 12.9 months. Median time-to-SBR was not reached in the R+TBRT group versus 17.4 months in the R+SRT group (HR 0.06; p=0.0070_. SB-RFS was improved with R+TBRT, with median of not reached versus 10.9 months with R+SRT (HR 0.48; p=0.0021). Overall adverse event did not differ between the groups. The authors conclude that for patients with newly diagnosed brain metastases requiring resection, R+TBRT significantly improved SBR and SB-RFS compared with R+SRT.