Additional elastography-targeted biopsy improves the agreement between biopsy Gleason grade and Gleason grade at radical prostatectomy

Purpose

To assess whether real-time elastography-targeted biopsy (RTE-bx) may help to correctly assign Gleason grade at radical prostatectomy (RP) and to compare discriminant properties of systematic biopsy alone (sbx) versus combination with RTE-bx (comb-bx) to distinguish between postoperatively favorable (Gleason 3 + 3, pT2, Nx/0) and postoperatively unfavorable (Gleason ≥4 + 4) prostate cancer (PCa) at RP.

Patients and methods

Overall, 259 patients diagnosed with PCa at systematic biopsy in combination with RTE-bx underwent RP between 2008 and 2011. Gleason Score derived from sbx versus comb-bx was compared to the gold-standard RP, and discriminant properties were assessed. Specificity gains were examined for sbx versus comb-bx when the endpoint consisted of postoperatively favorable PCa at RP. Sensitivity gains were examined, when analyses focused on postoperatively unfavorable PCa.

Results

Comb-bx resulted in higher correct overall Gleason assignment (68.3 vs. 56.7 %, p = 0.008) than sbx. Similarly, lower rates of undergrading (21.2 vs. 36.3 %, p < 0.001) were recorded. Specificity gains with comb-bx were 10 % (92 vs. 82 %, p = 0.004) for postoperatively favorable PCa. Comb-bx resulted in 31 % sensitivity gains relative to sbx (94 vs. 63 %, p = 0.03), when postoperatively unfavorable PCa was the endpoint.

Conclusion

The agreement between biopsy and pathology Gleason Score was significantly higher for comb-bx than sbx. Additionally, comb-bx reduced the rate of false positives in the diagnosis of favorable PCa. Rates of correctly classified unfavorable PCa at RP were also higher for comb-bx. Those data indicate that comb-bx is useful in clinical practice.