Single-fraction HDR brachytherapy as monotherapy in low and intermediate risk prostate cancer: Outcomes from two clinical trials with and without an MRI-guided boost

Highlights: • Single fraction high dose-rate brachytherapy has high local recurrence rate. • Dose escalation with an MR-guided boost to the dominant lesion does not improve outcome. • Single fraction protocols should not be used. Single-fraction HDR monotherapy for the treatment of localized prostate cancer is appealing, but published outcomes are discouraging. An approach to improve local control is MRI-guided focal dose-escalation to the dominant intraprostatic lesion (DIL). Here we report a comparison of outcomes from two phase II clinical trials with and without a focal boost.