Three-dimensional ultrasonography in evaluation of benign prostatic hyperplasia

Background: The clinical application of volume estimation by 3-D ultrasound has recently gained much attention. However, there have been no reports evaluating the prostate volume by 3-D transrectal ultrasound (TRUS) before transurethral resection of the prostate (TURP). The purpose of the present study was to evaluate the value of 3-D TRUS for prediction of prostate morphology and resected weight before TURP and to investigate whether 3-D TRUS is a more useful examination than 2D TRUS in patients with benign prostatic hyperplasia (BPH). Methods: Transurethral resection of the prostate was performed in 23 patients with BPH. We evaluated the prostate morphology and measured both the volumes of the whole prostate and the transition zone using 2-D and 3-D TRUS, respectively. The actual resected weight was recorded and compared with the volume of the whole prostate and that of the transition zone measured by 2D and 3-D TRUS. Results: The volume of the transition zone measured by 3-D TRUS correlated most strongly with the resected weight (r = 0.84). A large median lobe was seen in three patients in whom the transition zone volume measured by 2-D TRUS was considerably larger than the resected weight. However, overestimation in the three patients decreased by the use of 3-D TRUS. Conclusions: It was concluded that 3-D TRUS was equal or superior to 2-D TRUS in prediction of the resected weight and 3-D TRUS offers better information as a diagnostic tool before TURP.