Reassessment of nonplanimetric transrectal ultrasound prostate volume estimates

Objectives. To assess the accuracy and reproducibility of nonplanimetric transrectal ultrasound (TRUS) volume estimates because inaccurate volume estimates may potentially undermine the value of serum prostate-specific antigen density (PSAD) in early prostate cancer detection. Methods. We prospectively evaluated 535 consecutive male patients with two consecutive volume determinations performed by the same ultrasonographer at the time of the same visit. Results. Pearson correlation coefficients between two consecutive gland volume estimates ranged from 0.82 to 0.85 depending on the formula used; however, these correlation coefficients corresponded to an average 25% difference between the first and second gland volume estimates. Conclusions. Although two consecutive nonplanimetric TRUS volume estimates show statistically good correlation, clinically up to a 25% volume difference should be expected between two such volume estimates. In consequence, nonplanimetric TRUS volume estimates should be interpreted with caution, especially when used for PSAD calculation, in the early detection of prostate cancer.