Transition zone volume measurement – is it useful before surgery for benign prostatic hyperplasia?

Objective. The aim of this study was to estimate the equivalence and correlation between transition zone volume, measured by transrectal ultrasound, and removed prostate tissue weight in surgically treated patients due to benign prostatic hyperplasia.
Material and methods. This study involved 168 patients with histologically confirmed benign prostatic hyperplasia. Of these patients, 120 underwent transurethral resection of the prostate and 48 – open prostatectomy. The weights of the specimens were compared with the corresponding volumes of the transition zone. Equivalence and correlation between transition zone volume and removed tissue weight were analyzed.
Results. The mean (standard deviation, range) transition zone volume was 25.43 mL (±13.19, 5–61.6) in the transurethral resection group and 76.1 mL (±42.97, 13–275.8) in the open operation group. The mean removed tissue weight was 22.9 g (±13.41, 5–66) and 73.96 g (±44.96, 18– 280), respectively, in the transurethral resection and open operation groups. The correlation between removed tissue weight and transition zone volume was stronger in the open operation group than it was in the resection group (r=0.957, P<0.001 vs. r=0.878, P<0.001). There was a significant difference between transition zone volume and resected tissue weight (P=0.001). However, in the open operation group, there was an agreement between transition zone volume and enucleated tissue weight (P=0.263).
Conclusions. A significant correlation was detected between removed tissue weight and transition zone volume. There is a significant difference between volume measurement and resected tissue weight while enucleated tissue weight was in agreement with transition zone volume when an open prostatectomy was performed.