Outcomes of MRI fusion-guided versus systematic standard prostate biopsies

The current utility of MRI-fusion targeted biopsy as either an adjunct to or replacement for systematic template biopsy for the detection of clinically significant prostate cancer is disputed. The purpose of this study is to assess the current effectiveness of MRI-targeted versus systematic template prostate biopsies at two institutions and to consider possible underlying factors that could impact variability between detection rates in our patient population compared to others.

A retrospective review from our prospectively maintained prostate cancer databases was conducted. Patients with prostate MRI lesions (PI-RADSv2) receiving concurrent systematic 12-core and MRI-fusion targeted biopsies were reviewed. Clinically significant cancer was considered to be Grade Group ≥ 2.

A total of 457 patients were included in the analysis; 255 patients received their biopsy at Institution A and 202 at Institution B. Overall cancer detection rate was 68%; the clinically significant cancer detection rate was 34%. Both MRI-targeted and systematic biopsies identified unique cases of clinically significant prostate cancer that the other modality missed. Out of 157 cases of clinically significant prostate cancer, MRI-targeted biopsy identified 29/157 cases (18%) missed by systematic biopsy, while systematic biopsy identified 37/157 cases (24%) missed by MRI-targeted biopsy (p = .39). Individual biopsy performance was similar when stratified by active surveillance or prior biopsy status, PI-RADSv2 score, and institution.

MRI-fusion targeted and systematic biopsy each identified unique cases of clinically significant prostate cancer. Both biopsy modalities should be utilized in order to provide the greatest sensitivity for the detection of clinically significant prostate cancer.