Resistive index of prostatic capsular arteries as a predictor of prostate cancer in patients undergoing initial prostate biopsy.

To evaluate the value of resistive index (RI) of prostatic capsular arteries in diagnosis and evaluation of prostate cancer (PCa) in Chinese patients undergoing initial prostate biopsy. A total of 532 consecutive patients undergoing prostate biopsy were enrolled in this study. RI was measured on the largest transverse section of prostate for each individual. The predictive value of RI was evaluated using multivariate logistic regression and receiver operating characteristic (ROC) curve analyses. PCa was identified in 217 (40.79%) patients. RI was 0.69 ± 0.08 and 0.8 ± 0.08 for patients without and with PCa (p < 0.01). On logistic regression RI was significantly associated with PCa (p < 0.01). Using ROC analysis RI outperformed tPSA in prediction of PCa in all patients [area under ROC curve (AUC) = 0.83, 0.78, respectively]. With the cutoff value of 0.73, RI discriminated PCa from non-PCa patients with 81.9% sensitivity, 75.9% specificity and 77.63% diagnostic accuracy. Furthermore, The AUC for RI in the discrimination of PCa from non-PCa patients in a subset with PSA of 4 to 10 ng/ml, high grade from non-high grade PCa patients and advanced from localized PCa patients was 0.70, 0.77 and 0.80, higher than other parameters (p < 0.05). RI is proved a practicable parameter in identifying patients at risk for PCa and predicting the grade and stage of PCa before initial prostate biopsy. The value of RI should be further explored in the future.

Resistive index of prostate capsular arteries: a newly identified parameter to diagnose and assess bladder outlet obstruction in patients with benign prostatic hyperplasia.

PURPOSE: We evaluated the association of the resistive index of the prostate capsular arteries and bladder outlet obstruction severity in men with benign prostatic hyperplasia. MATERIALS AND METHODS: A total of 74 patients histologically diagnosed with benign prostatic hyperplasia were ultimately enrolled in this prospective study. Urodynamics were performed by a urologist to determine bladder outlet obstruction. Baseline parameters measured in patients with benign prostatic hyperplasia were the prostate capsular artery resistive index, International Prostate Symptom Score, quality of life score, total prostate and transition zone volume, and the transition zone index. ROC curves were produced to calculate the ROC AUC and evaluate the diagnostic performance of the prostate capsular artery resistive index, International Prostate Symptom Score, obstructive symptoms, total prostate and transition zone volume, and the transition zone index for bladder outlet obstruction. RESULTS: Significant difference between patients with and without bladder outlet obstruction was observed in the resistive index, which showed the highest coefficient with the degree of obstruction (r = 0.712, p <0.0001). At a cutoff of 0.69 the resistive index distinguished patients with and without bladder outlet obstruction with 78% sensitivity and 86.4% specificity. The prostate capsular artery resistive index had the maximum AUC of 0.823. CONCLUSIONS: The prostate capsular artery resistive index is significantly higher in patients with benign prostatic hyperplasia related bladder outlet obstruction than in those without such obstruction. The resistive index might serve as a novel indicator to diagnose and assess bladder outlet obstruction in patients with benign prostatic hyperplasia.