Multiparametric Magnetic Resonance Imaging/Ultrasound Fusion Prostate Biopsy-Are 2 Biopsy Cores per Magnetic Resonance Imaging Lesion Required?

PURPOSE: For multiparametric magnetic resonance imaging/ultrasound fusion prostate biopsy the number of biopsy cores obtained is arbitrarily established by urologists. Moreover, a general consensus is lacking on the number of biopsy cores to be obtained from a single magnetic resonance imaging lesion. Therefore, we evaluated the feasibility of obtaining only 1 biopsy core per magnetic resonance imaging lesion.

MATERIALS AND METHODS: We retrospectively evaluated a total of 2,128 biopsy cores of 1,064 prostatic lesions (2 cores per lesion) in 418 patients in regard to prostate cancer detection (histology) and the Gleason score of the first biopsy core compared to the second biopsy core. Two analyses were performed, including patient level analysis based on prostate cancer detection per patient and lesion level analysis based exclusively on the histology of each lesion regardless of the overall histological outcome of the case.

RESULTS: The overall prostate cancer detection rate was 45.7% (191 of 418 patients). The first biopsy core detected 170 of all 191 prostate cancers (89%). In 17 of these 170 prostate cancers (10%) the second biopsy core revealed Gleason score upgrading. Nine of the 21 prostate cancers (43%) missed by the first biopsy core had a Gleason score of 6. Altogether 537 of the 2,128 biopsy cores were positive, including 283 first (26.6%) and 254 second (24%) biopsy cores (p ≤0.001). The concordance between the first and second biopsy cores was 89% (κ = 0.71). There was a discrepancy with Gleason score upgrading in 28 of 212 lesions (13.2%) with positive first and second biopsy cores.

CONCLUSIONS: Our study shows that obtaining more than 1 biopsy core per magnetic resonance imaging lesion only slightly improves the prostate cancer detection rate and Gleason grading.