Limitations of Elastography Based Prostate Biopsy.

ABSTRACT

PURPOSE: The role of elastography in patients initially and at repeat prostate biopsy is still indeterminate. The existing literature is sparse and controversial. MATERIALS AND METHODS: We studied patients who underwent elastography based and systematic biopsy between October 2009 and February 2015 at Braunschweig Prostate Cancer Center. Patients were separated according to first vs repeat biopsy setting. Each prostate sextant was considered an individual case. The sensitivity, specificity, positive and negative predictive values, and accuracy of elastography to predict biopsy results were analyzed. The 95% CIs were determined by bootstrapping analysis of 2,000 samples. RESULTS: Overall 679 men and a total of 4,074 sextants were identified. Of the 679 men 160 (23.6%) underwent first biopsy and 519 (76.4%) underwent repeat biopsy. In the 160 men at first biopsy sensitivity was 18.0% (95% CI 14.5-21.3), specificity was 87.7% (95% CI 85.3-89.9), positive predictive value was 36.6% (95% CI 28.4-45.4), negative predictive value was 73.0% (95% CI 67.5-77.9) and accuracy was 67.9% (95% CI 63.4-72.2). Results in 519 men (76.4%) at repeat biopsy were 19.8% (95% CI 16.0-23.7), 90.9% (95% CI 89.9-91.9), 20.1% (95% CI 15.8-24.8), 90.7% (95% CI 89.0-92.3) and 83.5% (95% CI 81.6-85.2), respectively. CONCLUSIONS: We found limited reliability of elastography prediction at prostate biopsy in patients at first and repeat biopsies. Based on our analyses we cannot recommend a variation of well established systematic biopsy patterns or a decrease in biopsy cores based on elastography.