AUA 2019: Internal and External Validation of a 90-Day Percentage Erection Fullness Score Model Predicting Potency Recovery Following Robot-Assisted Radical Prostatectomy

Chicago, IL (UroToday.com) Linda My Huynh, Clinical Research Coordinator at UC Irvine, presented an internal and external validation of 90-day percentage erection fullness (EF) score. In the teams previous % fullness model from 2018, they found that patients reporting a 0-24% erection fullness score post-RP were 6 times more likely to suffer from long term impotence. This model was re-developed with a 1- and 2-year potency endpoint, as an adjunct to the IIEF-5.

Huynh defined potency as affirmative answers to erections sufficient for intercourse (ESI). In this study, 297 patients undergoing RARP, with a preoperative International Index of Erectile Function 5 (IIEF-5) score of 22 to 25 were set at a ratio of 2:1 for internal validation. Thereafter, a multi-center cohort of 91 patients under 5 surgeons were prospectively analyzed for external validation.

Results showed that percent of fullness was significantly associated with potency recovery (AUC=0.875) in internal validation. In ROC curve analysis of 90-day percent erection fullness, predicting 24-month potency showed a 25% erection fullness threshold with a sensitivity and specificity of 97.3% and 87.3%, respectively, for predicting recovery (AUC=0.870). Similarly, in predicting 12-month potency, ROC curve analysis showed a 25% erection fullness threshold with a sensitivity and specificity of 97.3% and 87.3%, respectively, for predicting recovery (AUC=0.801). The mean predicted probability of 1-year potency recovery was 39.7%± 3.2%, which was compared to a small difference of an actual 36.26% of patients recovering potency at 1 year.

Huynh emphasizes that percent erection fullness is able to discriminate post-RP recovery of EF well, between patients with a low vs high probability. She concludes that this allows surgeons an advantage at 90-days post-RP to stratify patients who are most likely to benefit from early rehabilitation.


Presented by: Linda Huynh, M.S. in Biomedical and Translational Sciences (MS-BATS); B.S in Public Health Sciences; the University of California-Irvine, Irvine, California

Written by: Kaelyn See, (Department of Urology, University of California-Irvine) medical writer for UroToday.com at the American Urological Association's 2019 Annual Meeting (AUA 2019), May 3 – 6, 2019 in Chicago, Illinois