Evaluation of prostate cancer detection with ultrasound real-time elastography: a comparison with step section pathological analysis after radical prostatectomy.

BACKGROUND

Conventional gray scale ultrasound has a low sensitivity and specificity for prostate cancer detection. Better imaging modalities are needed.

OBJECTIVE

To determine sensitivity and specificity for prostate cancer detection with ultrasound-based real-time elastography (elastography) in patients scheduled for radical prostatectomy (RP).

DESIGN, SETTING, AND PARTICIPANTS: Between July and October 2007, 109 patients with biopsy-proven localized prostate cancer (PCa) underwent elastography before RP. The investigator was blinded to clinical data.

MEASUREMENTS

A EUB-6500HV ultrasound system with a V53W 7.5MHz end-fire transrectal probe was used preoperatively. Areas found to be suspicious for PCa were recorded for left and right side of the apex, mid-gland, and base. These findings were correlated with the obtained whole-mount sections after RP.

RESULTS AND LIMITATIONS

Sensitivity and specificity for detecting PCa were 75.4% and 76.6%, respectively. A total of 439 suspicious areas in elastography were recorded, and 451 cancerous areas were found in the RP specimens. Positive predictive value, negative predictive value, and accuracy for elastography were 87.8%, 59%, and 76%, respectively. Nevertheless, there are limitations to our studies because we investigated specific patients scheduled for RP with apparent PCa. Whether elastography is practical as a diagnostic tool or can be used to target a biopsy and be at least as sensitive in tumor detection as extended biopsy schemes has yet to be determined.

CONCLUSION

Elastography can detect prostate cancer foci within the prostate with good accuracy and has potential to increase ultrasound-based PCa detection. Further studies need to be done to approve these data and to evaluate whether tumor detection can be increased by elastography-guided biopsies.