Marieke van Son

115 QOL AFTER ULTRAFOCAL SALVAGE HDR-BRACHYTHERAPY to our urethral dose constraint (17.7 Gy) to account for the more frequently occurring moderate urinary symptoms. Following our cut-off analysis, a lower constraint might be an improvement. For the sexual functioning domain, surprisingly age was not a significant predictor for HR-QoL deterioration, showing that sexual functioning varies among men of similar ages. Interestingly, the level of sexual activity did not seem to be affected over time. It has been suggested that substantial radiation dose to the dorsolaterally situated neurovascular bundles (NVBs) may cause erectile dysfunction(20). Although we expect the dose to the NVBs to be relatively low with ultrafocal HDR-BT, 87/100 patients had a dorsolaterally located tumor, of which 25% was bilateral. Due to a lack of clear guide- lines on identification and delineation of the NVBs, we were not able to directly assess the relation with NVB received dose. Although outside the scope of this patient-reported outcome study, a recent com- parative trial has raised concerns about the oncological effectiveness of a single-dose HDR-BT regimen in the primary setting. This trial randomized 170 patients between whole-gland 1x19Gy and 2x13.5Gy and reported 5-year biochemical control rates of 73.5% (single-dose) versus 95% (two-fraction)(21), with similar low morbidity(22). Un- fortunately, there is no comparative data available on single-dose versus two-fraction focal salvage HDR-BT. It is therefore too early to suggest that this translates to the (focal) salvage setting. A limitation of this study is the relatively short follow-up time. Although it is not ex- pected, late treatment effects from delayed radiation damage may cause more HR-QoL deterioration in the future. Strengths of this study include the prospective nature, the high questionnaire response rates and the large patient group included in the analysis. CONCLUSION In conclusion, ultrafocal salvage HDR-BT seems to have a transient effect on patient-re- ported urinary function and no clinical effect on patient-reported bowel function. While sexual activity does not seem to decrease, patients report a deterioration of sexual functioning over time. Patients with impaired function at baseline (increased urinary symptoms or decreased sexual functioning) may have a higher risk of domain-specif- ic HR-QoL deterioration over time, showing the importance of symptom assessment before treatment. Radiation dose to the urethra should be kept at a minimum to avoid urinary symptoms after treatment. This information may be used to improve treatment planning and patient counseling before treatment. 6