Prostate cancer: a comparison of the diagnostic performance of transrectal ultrasound versus contrast enhanced transrectal ultrasound in different clinical characteristics

Abstract

To determine whether contrast-enhanced transrectal ultrasound (CE-TRUS) is superior to transrectal ultrasound (TRUS) on diagnosis of prostate cancer, 317 patients were processed TRUS examination with or without SonoVue, then biopsy was performed. Sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) of two techniques were compared in multiple subgroups of PSA level, Digital rectal examination (DRE) and prostate volume on biopsy results. In PSA 4-10 ng/ml and DRE negative groups, CE-TRUS had greater sensitivity and accuracy compared with TRUS by patient (P = .004 and .003; .013 and .005 respectively) and greater sensitivity, accuracy, PPV and NPV by core. When prostate volume was 45-65 ml, CE-TRUS had greater specificity and accuracy by patient and all diagnostic performances were statistically significant by core. CE-TRUS is superior to TRUS on diagnosis of prostate cancer in a designed patient population with lower PSA level, DRE negative findings and modest prostate volume.

Keywords: Prostate cancer; biopsy; contrast agent; ultrasound.

Figure 1

Images acquired from a patient with clinical characteristics of 28.00 ng/ml PSA level, DRE positive of left gland, 84 years old and 33 ml prostate volume. Grey-scale image shows hypoechoic lesions in the left base (A1), mid (B1) and apex (C1) gland (arrows). Power Doppler image shows increased vessels in these areas (A2, B2, C2 respectively). Contrast enhanced ultrasound image shows rapidly enhancing lesions with greater contrast in these areas (A3, B3, C3 respectively) compared with corresponding left gland (arrows). Biopsy targeted to these suspicious areas reveals Gleason 7 prostate cancer. Moreover, contrast enhanced ultrasound image shows a low enhancement area in the right mid gland (arrow) compared with surrounding peripheral zone tissues. Biopsy targeted to this suspicious area reveals Gleason 7 prostate cancer.