Treatment cycles per unit prostate volume (CPV) for transurethral water vapor therapy (Rezūm) in catheter-dependent...

For transurethral water vapor therapy (Rezūm), the number of water vapor treatment cycles has classically been determined by the prostate length, or the fields of vision (FOV). Apart from treating lower urinary tract symptoms, there is emerging evidence on Rezūm for refractory retention. We aim to investigate the optimal number of treatment cycles for Rezūm in catheter-dependent refractory retention.

From 02/2021 to 09/2023, 168 consecutive catheter-dependent patients undergoing Rezūm at three centres were included in this prospective registry. Treatment Cycles Per Unit Prostate Volume (CPV) was calculated by dividing the number of treatment cycles by the prostate size. After propensity score matching of age and prostate size, 144 patients were analyzed in the CPV ≤ 0.15 and CPV > 0.15 groups in 1:1 ratio. The primary outcome was the International Prostate Symptom Score (IPSS) at 1-year follow-up. Secondary outcomes included catheter removal time, 30-day readmission rates, prostate-specific antigen (PSA) reduction. Logistic regression model and linear mixed model were used.

The CPV > 0.15 group demonstrated significantly better IPSS at 1-year follow-up (adjusted mean difference -2.8 points, p = 0.040), and lower 30-day readmission rates (4.2% vs 16.7%, OR 0.22, p = 0.029). Greater PSA reduction was observed in the higher CPV group at 3 months (adjusted mean difference of log-transformed PSA: -0.4 ng/ml, p = 0.022). Median catheter removal times were 14 days (interquartile range 9-29 days) and 15 days (interquartile range 12-40 days) for lower and higher CPV groups respectively (p = 0.059). Six-week IPSS and IPSS-QoL (quality of life score) were similar (p = 0.359 and p = 0.464 respectively).

Higher CPV (>0.15) in Rezūm demonstrated superior 1-year IPSS, lower 30-day readmission rates in our matched cohort. A more aggressive treatment approach, contrasting to the standard FOV-based approach, may benefit catheter-dependent patients.