Validation of supra-pubic ultrasonography for preoperative prostate volume measurement in sub-Saharan Africa.

BACKGROUND

Advances in urological techniques in sub-Saharan Africa need to be supported with practical ancillary diagnostics. This study aimed at determining the accuracy of suprapubic ultrasonography (SPUS) relative to transrectal ultrasonography (TRUS), the current gold standard, in estimating preoperative prostate volume in a sub-Saharan African hospital.

METHODS

Cross-sectional study of prospectively enrolled patients with severe lower urinary tract symptoms and histologically confirmed benign prostatic hyperplasia. The volume of the prostate was estimated using two modalities, SPUS and TRUS. Open prostatectomy was performed on all patients, and the mass of the enucleated prostate adenoma was measured directly.

RESULTS

Fifty patients were enrolled, with a mean age of 69 years. The mean prostate volume as determined by TRUS, SPUS, and direct measurement of enucleated prostatic tissue was 96.0, 95.9 and 83.5 mL, respectively. Prostate volume determined by SPUS correlated strongly with the TRUS measurement (ρ = 0.98, P < 0.001). The mean difference between the volume estimates by TRUS and SPUS was 0.09 mL [95% CI -2.07 to 1.89, P = 0.93], with upper and lower limits of agreement of -13.8 and +13.6 mL, respectively. Sensitivity, specificity, positive and negative predictive value for SPUS relative to TRUS for classifying patients according to the indication for TURP (prostate volume ≤80 mL) versus open prostatectomy (>80 mL) were 95% or higher. The volume of the enucleated adenoma was less than the volume estimated by ultrasonography by approximately 12.5 mL.

CONCLUSION

SPUS is accurate relative to TRUS in assessing preoperative volume of the prostate and can be used in the African context to assign patients to open prostatectomy or TURP.