Performance Characteristics of 3-D Power Doppler Ultrasound (3-D-PD) with the Virtual Organ Computer-Aided Analysis (VOCAL) Technique in the Detection of Prostate Cancer.

Abstract

The purpose of this study was to test the diagnostic performance of 3-D power Doppler ultrasound (3-D-PD) with the virtual organ computer-aided analysis (VOCAL) technique in the detection of prostate cancers (PCa). A total of 99 male patients referred for needle prostate biopsy owing to elevated serum prostate-specific antigen or abnormal direct rectal examination were prospectively included. The transrectal 3-D-PD-VOCAL quantitative vascularity parameters of vascularization index (VI), flow index and vascularization/flow index (VFI) were obtained before biopsy and compared with histopathologic results. We evaluated the predictive values for the detection of clinically significant PCa in the foci from different zones and the discrimination among various cancer grades. 3-D-PD-VOCAL discriminated malignant from benign foci, with cutoff values of 27.4% for VI, 38.2 for flow index and 8.6 for VFI. All parameters had higher areas under the curve in detecting lesions in the peripheral zone than in the transition zone (p < 0.05). VI and VFI had better diagnostic performance in detecting clinically significant PCa than flow index (p < 0.05). The area under the curve, sensitivity, specificity and accuracy in detecting clinically significant PCa were, for the VI and VFI respectively, 95% and 95%, 86% and 94%, 87% and 76%, and 87% and 85%. 3-D-PD-VOCAL initially demonstrated favorable performance in detecting PCa. Further, larger-sample studies based on prostatectomy specimens are needed to evaluate the exact usefulness of the technique.