You have accessJournal of UrologyCME1 Apr 2023MP59-16 MAGNETIC RESONANCE IMAGING TRANSITION ZONE VOLUME IS HIGHLY CONCORDANT WITH ENUCLEATED VOLUME AFTER HOLMIUM LASER ENUCLEATION OF THE PROSTATE DUE TO VARIATION IN THE TRANSITION ZONE INDEX Jordan Krieger, Margaret A Knoedler, Shane A Wells, Ali S Antar, Ethan Richmond, Trevor L Everett, Alex G Thomas, Christopher M Manakas, Daniel R Gralnek, and Matthew D Grimes Jordan KriegerJordan Krieger More articles by this author , Margaret A KnoedlerMargaret A Knoedler More articles by this author , Shane A WellsShane A Wells More articles by this author , Ali S AntarAli S Antar More articles by this author , Ethan RichmondEthan Richmond More articles by this author , Trevor L EverettTrevor L Everett More articles by this author , Alex G ThomasAlex G Thomas More articles by this author , Christopher M ManakasChristopher M Manakas More articles by this author , Daniel R GralnekDaniel R Gralnek More articles by this author , and Matthew D GrimesMatthew D Grimes More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003312.16AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Holmium laser enucleation of the prostate (HoLEP) aims to remove the entire prostate transition zone. Whole prostate gland volume (WGV) is often used to predict HoLEP enucleated volume. However, WGV and enucleated volume are sometimes discordant implying variability in the ratio of transition zone volume (TZV) to WGV (transition zone index, TZI). We aim to determine the relationship between TZI and WGV and assess the concordance between HoLEP enucleated volume and MRI estimated WGV and TZV. METHODS: A prospective HoLEP database was queried to identify patients with MRI within one year of HoLEP. TZI was calculated by dividing TZV by WGV. Patients were categorically stratified based on ellipsoid WGV, as measured by a radiologist. The ratio between TZI and WGV was assessed using stratified analysis and regression. Concordance was defined as the ratio of enucleated volume to WGV and TZV with mean values compared using ANOVA. RESULTS: We analyzed 218 patients with mean WGV of 101g (range 16.7 - 388) and TZV of 63.6g (range 6.06 - 346). TZV was more concordant with enucleated volume compared to WGV (mean 0.984, SD 0.297) vs 0.56 (SD 0.187, p<0.001). Mean TZI and enucleated specimen concordance all varied significantly when stratified by prostate volume (Table 1). Regression analysis revealed a significant, positive, non-linear relationship between WGV and TZI, but with high variability between individual patients (r=0.62) (Figure 1). CONCLUSIONS: MRI transition zone volume measurements are highly concordant with HoLEP enucleated volumes, especially when compared with whole gland volume measurements. On average, larger prostates have a higher TZI, but TZI is highly variable in individual patients and may not be accurately predicted from WGV alone. Therefore, preoperative transition zone measurement with MRI provides a valuable, accurate, and non-invasive tool for estimating enucleated volume prior to HoLEP. Source of Funding: None © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e814 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Jordan Krieger More articles by this author Margaret A Knoedler More articles by this author Shane A Wells More articles by this author Ali S Antar More articles by this author Ethan Richmond More articles by this author Trevor L Everett More articles by this author Alex G Thomas More articles by this author Christopher M Manakas More articles by this author Daniel R Gralnek More articles by this author Matthew D Grimes More articles by this author Expand All Advertisement PDF downloadLoading ...