What is the best radiological method to predict the actual weight of the prostate?

We compared the weight of the prostate specimen extracted after radical prostatectomy with preoperatively estimated weights of the prostate by different imaging techniques.

Prostate weights were estimated by transabdominal ultrasonography (TAUS), transrectal ultrasonography (TRUS), and computed tomography (CT) preoperatively before radical prostatectomy. Prostatectomy specimens were weighed postoperatively and the actual prostate weights were calculated. Statistical analyses were done using 95% confidence intervals with repeated measurement analysis of variance and intraclass correlation coefficients.

Of the 163 patients enrolled in the study, the mean age was 64.2 +/- 6.4 (range: 45 to 76) years. The mean postoperative prostate weight was 54.7 +/- 27.9 g. Preoperative mean prostate volumes calculated by TAUS, TRUS, and CT were 50.2 +/- 24.1, 50.7 +/- 24.6, and 62.7 +/- 28.2 mL, respectively (P < 0.001). The actual prostate weight measured using an electronic scale was correlated with the estimated prostate weight in each of 3 methods, the best of which was that of TRUS.

The actual prostate weight is best estimated by measurements done with TRUS. However, clinicians should consider that some errors and deviations may occur with these imaging techniques.