Prostate volume on transrectal ultrasound: comparing ultrasounds performed by urologists to radiologists

This study aims to assess the precision of transrectal ultrasound (TRUS) measurement of the prostate volume when performed by a urologist compared with a radiologist. To date, no prior research has directly compared the accuracy of prostate volume measurements between these two groups.

A retrospective study was conducted using data from 307 men who underwent enucleation of the prostate between 2020 and 2022 in two Belgian hospitals (University Hospital Leuven and Maria Middelares Hospital [Ghent]). A comparison was made between the prostate volume measured on ultrasound pre-operatively and the measured resected volume after enucleation. We compared these differences in volume in men who had their ultrasound performed by a urologist (N = 114), those who had it performed by a radiologist (N = 175), and those who had an MRI pre-operatively as a measurement (N = 18).

A multivariate regression to predict measured prostate volume was performed with age, estimated prostate volume, and pathology result as predictors, which was significant at α = 0.05, F(3, 302) = 168.104, p < 0.001, RAdjusted2 = 0.686. Adding the imaging modality (ultrasound performed by a urologist or radiologist, or MRI) to the base model did not significantly improve the prediction of measured prostate volume, F-change(3, 299) = 0.367, p = 0.777. Seven outliers were identified (|Z-score| > 2), of which six measurements were performed by resident urologists (N = 19) and one by a certified urologist (N = 95).

This study demonstrates no evidence that prostate volume measurements performed by radiologists using ultrasound are more accurate than those performed by urologists. The higher number of outliers among resident urologists likely reflects the well-known learning curve associated with prostate ultrasound and highlights the importance of standardized training.