Propensity score matched analysis of functional outcome in 5000 cases of robot-assisted radical prostatectomy versus high-intensity focused ultrasound

Background To evaluate functional outcome after robot-assisted radical prostatectomy (RARP) and high-intensity focused ultrasound (HIFU) ablation for prostate cancer. Methods We retrospectively reviewed 4,983 RARP and 230 HIFU procedures performed at a single tertiary center. A 1:4 ratio propensity score matching (PSM) was performed to achieve baseline equivalence in age, BMI, comorbidities, clinical stage, PSA, prostate volume, biopsy grade, and number of positive cores. Functional outcomes based on IPSS (international prostate symptom score), IIEF-5 (international index of erectile function) scores, and incontinence rates were evaluated at 6, 12, and 24 months. Results Total 193 HIFU cases matched to 760 cases of RARP were included. No differences were observed in perioperative IPSS at all follow-up periods. Despite comparative erectile function at baseline, HIFU showed significantly better erectile function preservation compared to RARP, with mean IIEF-5 scores 9.5 vs 4.8, 9.5 vs. 5.8, and 8.4 vs. 6.7 at 6, 12, and 24 months, respectively (all p<0.001). Pad-free rates at 6 and 12 months were comparable, with over 96% achieving continence at 12 months in both groups, although rate of ≤1 pad/day at last follow-up was slightly better in HIFU (98.9% vs. 96.7%, p=0.049). Subgroup analysis on partial (PGA) and whole gland ablation (WGA) showed no differences in IIEF-5 and incontinence but increased voiding difficulty in WGA vs. PGA after 12 months of therapy (p<0.05). Preoperative IIEF-5≥17 and HIFU were significant predictors of early erectile function recovery at 6 months (HR 4.4 and 5.0; all p<0.001). No differences were observed in treatment-free survival between PGA, WGA, and RARP. Conclusion HIFU shows better performance in early recovery and preservation of erectile function after treatment for prostate cancer without increased risk of treatment-failure. Patients with moderate to severe erectile dysfunction (IIEF-5 <17) prior to surgery should be warned of poor recovery after treatment.