Contrast-enhanced sonography for prostate cancer detection in patients with indeterminate clinical findings

The purpose of our study was to evaluate the usefulness of contrast-enhanced sonography for prostate cancer detection in patients with an indeterminate prostate-specific antigen (PSA) level (4-10 ng/mL) and negative findings on digital rectal examination.

Forty-eight patients underwent gray-scale, color Doppler, and contrast-enhanced sonography examinations and then sonographically guided biopsy. Contrast-enhanced sonography was performed using Levovist at a mechanical index of 1.1-1.4. The performances of the three methods for cancer detection were compared according to biopsy site and patient.

Sensitivity by biopsy site was greater on contrast-enhanced sonography (68%) than on gray-scale (39%) and color Doppler (41%) sonography (p > or = 0.05), whereas the specificity and overall accuracy by biopsy site (82% and 77% for gray-scale sonography, 84% and 79% for color Doppler sonography, and 83% and 81% for contrast-enhanced sonography, respectively) were not different for the three methods (p > 0.05). The concordance score for sonography and biopsy results by patient was not different for gray-scale (6.4 +/- 1.8), color Doppler (6.3 +/- 0.6), and contrast-enhanced sonography (6.5 +/- 0.7) (p = 0.281).

Contrast-enhanced sonography could improve only the sensitivity for cancer detection in analysis by biopsy site but did not improve the overall performance of sonography in patients with an indeterminate PSA level and negative digital rectal examination.