RESUMO
PURPOSE: There is debate whether transition zone index is correlated with the parameters of benign prostatic hyperplasia. The purpose of this study was 3-fold: 1) to determine if transition zone index is correlated with the symptom score and peak flow rates of clinical benign prostatic hyperplasia, 2) to determine if transition zone index is correlated with the symptom score and peak flow rates of clinical benign prostatic hyperplasia after TURP, and lastly 3) to determine if the improvement of symptom score and peak flow rates after TURP is different according to transition zone index. MATERIALS AND METHODS: Fifty eight men, who underwent TURP, were measured total prostate volume and transition zone volume by trasnsrectal ultrasonography. All men were requested to undergo uroflowmetry and intermational prostate symptom score(IPSS), before and after TURP. RESULTS: The significant correlation between transition zone index and IPSS(p = 0.0001, R2 = 0.3652), and the relationships between transition zone index versus peak flow were not statistically significant(p = 0.79, R2 = 0.0015) before TURP. A weak relationship was observed between transition zone index versus IPSS(p = 0.0019, R2 = 0.16), peak flow rate(p = 0.022, R2 = 0.0811) after TURP. The improvement of IPSS and peak flow rate showed statistically significant difference according to transition zone index(p = 0.0001, 0.0787) CONCLUSIONS: The higher transition zone index, the more favorable outcome of transurethral resection of prostate was expected. On the contrary, the lower transition zone index, the less favorable outcome. So transition zone index can be used as a factor predicting the outcome of transurethral resection of prostate. The patient with lower transition zone index may have other factors affecting improvement of symptoms and peak flow rate in addition to obstruction.