Marieke van Son

56 CHAPTER 3 considering all procedure steps: MRI/TRUS-guided insertion of catheters, subsequent transport to the MRI, catheter reconstruction and dose planning, another MRI scan for verification just before dose delivery and, if necessary, adjustment of the plan. In the future, MRI-guided external radiotherapy systems could provide hypofraction- ated ultrafocal stereotactic radiation treatment(32), potentially matching ultrafocal HDR-brachytherapy in terms of tumour control and morbidity. CONCLUSION MRI-guided ultrafocal HDR-brachytherapy for localised prostate cancer conveyed minimal grade 2 GU toxicity and no grade >1 GI toxicity. Erectile function significantly deteriorated over time, with a rapid decline after treatment. Accordingly, patient-re- ported QoL was marginally affected, although clinically relevant deteriorations were seen in the domains tiredness and sexual activity. After 4 years, BDFS was 70%. Even in the light of very low toxicity, this is an unfavourable outcome which predominantly seems to result from inadequate patient selection. However, the remaining potential for successful (focal or whole-gland) local salvage treatment may substantiate the use of focal therapy, especially if patient selection is improved in the future.