Magnetic resonance/transrectal ultrasound fusion biopsy of the prostate compared to systematic 12-core biopsy for the diagnosis and characterization of prostate cancer: multi-institutional retrospective analysis of 389 patients.

Objective: To determine the incremental diagnostic value of targeted biopsies added to an extended sextant biopsy scheme on a per-patient, risk-stratified basis in 2 academic centers using different multiparametric magnetic resonance imaging (MRI) protocols, a large group of radiologists, multiple biopsy systems, and different biopsy operators.

Materials And Methods: All patients with suspected prostate cancer (PCa) who underwent multiparametric MRI of the prostate in 2 academic centers between February 2013 and January 2015 followed by systematic and targeted MRI-transrectal ultrasound fusion biopsy were reviewed. Risk-stratified detection rate using systematic biopsies was compared with targeted biopsies on a per-patient basis. The McNemar test was used to compare diagnostic performance of the 2 approaches.

Results: A total of 389 men met eligibility criteria. PCa was diagnosed in 47% (182/389), 52%(202/389), and 60%(235/389) of patients using the targeted, systematic, and combined (targeted plus systematic) approach, respectively. Compared with systematic biopsy, targeted biopsy diagnosed 11% (37 vs. 26) more intermediate-to-high risk (P<0.0001) and 16% (10 vs. 16) fewer low-risk tumors (P<0.0001). These results were replicated when data from each center, biopsy-naïve patients, and men with previous negative biopsies were analyzed separately.

Conclusion: Targeted MRI-transrectal ultrasound fusion biopsy consistently improved the detection of clinically significant PCa in a large patient cohort with diverse equipment, protocols, radiologists, and biopsy operators as can be encountered in clinical practice.