To determine if transition zone (TZ) volume as measured by magnetic resonance imaging (MRI) correlates closely with specimen weight and postoperative prostate-specific antigen (PSA) and to determine if this correlation improved with increased experience. We hypothesize that information from a preoperative MRI can be leveraged to self-assess competency in holmium laser enucleation of the prostate (HoLEP).

From August 2018 to June 2021 567 men were identified who underwent HoLEP by a single surgeon and had their data entered into a database. Ninety-seven men were identified who had an MRI in our image archives. A radiologist blinded to the specimen weight measured the transition zone (TZ) using image analysis software. TZ volume was then correlated with specimen weight for the entire study period and subdivided into four consecutive periods. Preoperative and Postoperative PSA data was analyzed.

Seventeen percent of men who underwent HoLEP at our institution had an MRI preoperatively. The TZ to total prostate volume ratio was 70%. The overall correlation coefficient between TZ volume and specimen weight was 0.914 (P-value <.001). There was no statistically significant improvement in correlation coefficient over time when divided into four equal subgroups. Median PSA reduction was 91% (7.9-0.7 ng/dL).

Preoperative MRI derived TZ volume correlates closely with specimen weight. We present a reference cohort from a high volume HoLEP center to facilitate HoLEP learners to self-assess competency. Lack of increased correlation over time is likely due to an experienced HoLEP surgeon who is on the flatter portion of his learning curve.