Elastography Targeted Prostate Biopsy in Patients under Active Surveillance.

OBJECTIVE: The aim of this study was to examine elastography-based prostate biopsy in prostate cancer (PCa) patients under active surveillance. PATIENTS AND METHODS: We relied on PCa patients who opted for active surveillance and underwent elastography targeted and systematic follow-up biopsy at the Braunschweig Prostate Cancer Center between October 2009 and February 2015. Each prostate sextant was considered as an individual case. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy (ACC) for elastography to predict follow-up biopsy results were analyzed, respectively, and 95 % confidence intervals (CIs) were carried out by using 2000 bootstrapping sample analyses. RESULTS: Overall, 50 men and 300 sextants were identified. Overall, 27 (54%) men and 66 (22%) sextants harbored PCa at follow-up biopsy. Sensitivity, specificity, PPV, NPV, and ACC for elastography to predict follow-up biopsy results were: 19.7 (95% CI: 11.9-27.3), 86.8 (95% CI: 82.7-90.3), 29.6 (95% CI: 14.6-46.0), 79.3 (95% CI: 71.6-86.5), and 72.0% (95% CI: 65.7-78.3), respectively. CONCLUSIONS: We recorded limited reliability of elastography-based prediction of follow-up biopsy results in active surveillance patients. Based on our analyses, we can neither recommend to rely exclusively on elastography-based targeted biopsies nor to delay or to omit follow-up biopsies based on elastography results during active surveillance.

Limitations of Elastography Based Prostate Biopsy.

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.