Three-dimensional contrast-enhanced power Doppler ultrasonography and conventional examination methods: the value of diagnostic predictors of prostate cancer

Objective To investigate the value of three-dimensional contrast-enhanced p ower Doppler ultrasonography (3D-CE-PDU) in the diagnosis of prostate cance r and to compare 3D-CE-PDU with digital rectal examination (DRE), prostate- specific antigen (PSA) levels, grey-scale ultrasonography (GSU) and PDU. Patients and methods The study comprised 30 patients with localized prostat e cancer scheduled to undergo radical prostatectomy and 29 with clinical BP H scheduled to undergo transurethral microwave thermotherapy. The 3D-CE-PDU examinations were carried out using 2.5 g of microbubble ultrasound contra st medium; the images were stored digitally to allow off-line analysis. All the reconstructed 3D images of the prostate were evaluated blindly in rand om order by two investigators tone expert and one novice, The images were s cored according to asymmetry (0-2) and vessel distribution (0-3). Marked as ymmetry (2) and/or a focal increase in vascularity (>2) were considered as suspicious for prostate malignancy. Diagnostic predictions using the DRE, P SA level, GSU, PDU, 3D-CE-PDU and their combinations were investigated usin g receiver operating characteristic (ROC) curves. Results True-positive and true-negative rates of the 3D-CE-PDU were 87% (26 /30) and 79% (23/29), respectively, for the expert observer. The sensitivit y of 3D-CE-PDU was higher than that of DRE, GSU and PDU, but not PSA level, and the specificity was lower, again except for PSA level. However, when c ompared with those of the other modalities in single-test evaluations, 3D-C E-PDU, and a combination of 3D-CE-PDU and PSA level, had the largest area u nder the ROC curve (0.830 and 0.933, respectively). The diagnostic agreemen t between the examiners was 76% (Cohen kappa statistic, 0.5). Conclusion in this selected group of patients, 3D-CE-PDU alone was a better diagnostic tool than the DRE, PSA level, GSU or PDU alone. The most suitab le diagnostic predictor for prostate cancer was a combination of 3D-CE-PDU and PSA level.