Multicenter phase 3 trial of addition of focal boost to EBRT for localized prostate cancer: 10-year outcomes of FLAME

The multicenter phase 3 FLAME trial in The Netherlands randomized patients with intermediate- or high-risk localized prostate cancer to standard EBRT to the entire prostate with or without focal boost to the intraprostatic tumor lesions (visible on mpMRI). The 10-year biochemical disease-free survival (bDFS) was 71% in the standard group versus 86% in the focal boost group, with additional significant improvements for the endpoints disease-free survival (DFS), local DFS, regional lymph node DFS, but not for distant-metastasis-free survival or overall survival. However, the dose-response curve suggested an association between boost dose and distant metastatic failure. The authors conclude that these 10-year results demonstrated the sustained benefit of focal boosting on bDFS.