ABSTRACT
PURPOSE: Prostate volume has been known to be poorly correlated with various parameters used to assess the severity of benign prostatic hyperplasia (BPH). However, recently there were reports that the ratio between transition zone(TZ) volume and prostate volume, which termed the TZ index might served as a useful proxy for evaluating worsening obstruction. The purpose of this study was to determine if transrectal ultrasound(TRUS) measurement of RI(resistive index), PCAR (presumed circle area ratio) correlate with the parameters of prostate volume(total prostate volume, TZ volume, TZ index), Qmax, international prostate symptom score(IPSS) or age. This study was conducted to reveal the relative effects of ultrasonic appearance of BPH on urinary symptoms. MATERIALS AND METHODS: A total of 81 men aged 50 to 89 years with moderate symptom of BPH(IPSS> or =8) underwent measurement of RI, PCAR, total prostate and TZ volume at transrectal ultrasonography. All men were requested to undergo uroflowmetry and complete the IPSS. The IPSS was compared to age, Qmax, prostatic volume, RI and PCAR using simple and multiple regression analysis. RESULTS: Simple regression analysis demonstrated that IPSS correlated with age(r=0.050, p<0.05), Qmax(r=0.253, p<0.05), TV(r=0.096, p<0.05) and PCAR(r=0.266, p<0.05). However, multiple regression analysis showed that age, Qmax and PCAR were significant independent determinants of the IPSS. CONCLUSIONS: As a parameter representing the degree of BPH in terms of the severity of lower urinary symptoms, simple and multiple regression analysis confirmed that the IPSS was influenced considerably by age, peak flow rate and PCAR.