Marieke van Son

97 MRI-GUIDED ULTRAFOCAL SALVAGE HDR-BRACHYTHERAPY DISCUSSION From the first 50 patients treated with ultrafocal salvage HDR-BT, we report only 2% severe GU toxicity and no severe GI toxicity. Grade 2 GU toxicity occurred more fre- quently (52%), but was mostly manageable by medication, resulting in a stable pa- tient-reported IPSS over time. Severe ED occurred in 22% of patients, corresponding to a downward trend in IIEF-5 scores after treatment. QoL was not significantly affected. After 2.5 years, BDFS was 51% (95%-CI 37-69%), MFS was 75% (64-89%) and 90% had not started ADT (82-99%). These results are consistent with reports on focal salvage treatment modalities, namely LDR/HDR brachytherapy, cryotherapy, HIFU and stereotactic body radiother- apy (SBRT). 13 Severe GU/GI toxicity rarely (≤8%) occurs. The few studies reporting QoL describe a significant deterioration within the sexual domain (using the Expanded Prostate Cancer Index Composite [EPIC]), 14 and a significant increase in urinary symp- toms (using EORTC QLQ-PR25). 15 BDFS ranges from 56-92% at 1 year, to 22-61% at 3 years, to 47-54% at 5 years follow-up. 13 The main difference between focal treatment modalities is their accessibility to certain tumor locations: posterior lesions seem best approachable using HIFU, cryotherapy is more appropriate for anterior lesions and apical lesions can be safely treated with brachytherapy. 16 From our own experience, both intraprostatic tumors and seminal vesicle invasion (SVI) are well within reach for a focal brachytherapy implant. A recent review by Steele et al. showed there are higher and more severe toxici- ty rates from whole-gland salvage treatments, at similar tumor control rates (5-year BDFS approximately 50–60%). Salvage prostatectomy (total 709 patients, follow-up 3-7.2 years) caused 4-10% operative rectal injury, 22–41% postoperative bladder neck contractures and 48% urinary incontinence. Whole-gland salvage LDR-BT (total 311 patients, follow-up 4.5-9 years) caused 12-19% grade 3 GU/GI toxicity. In comparison, whole-gland HDR-BT (total 94 patients, follow-up 3-5 years) seemed less toxic with 2-7% grade 3 GU toxicity and no grade 3 GI toxicity. Whole-gland salvage cryothera- py (total 665 patients, follow-up 1.4- 7.5 years) resulted in 72% urinary incontinence (dribbling or leakage), 66% medium to severe obstructive symptoms and 8-10% com- plications requiring additional surgical intervention. Whole-gland salvage HIFU (total 1013 patients, follow-up 1.2-3.3 years) caused 6-9% urethrorectal fistula and 16-30% bladder outlet obstruction. 17 Despite its low toxicity profile, the role of focal salvage treatment for radiorecurrent prostate cancer is yet to be determined. Longer follow-up data is warranted to assess the effectiveness in terms of oncologic control and delay time to ADT. Herein, there are several aspects to evaluate. First, adequate patient selection is crucial. Within our cohort, failing patients were slightly younger at the time of treatment (median 70 versus 73 years), had a higher Gleason grade (54% versus 29% ³4+3=7), higher pre-salvage PSA (median 5.5 versus 4.2 ng/ml), shorter PSADT (median 16.5 versus 19 months) and more advanced T-stage 5