Does experience change the role of systematic biopsy during MRI-fusion biopsy of the prostate?

Purpose: To determine the role of biopsy experience regarding a potential benefit of additional systematic biopsies and fusion failures during MRI-targeted biopsy of the prostate. Subjects/patients and methods: We retrospectively evaluated 576 men undergoing transrectal (MRI)-targeted biopsy of the prostate by seven residents in urology between November 2019 and March 2022. Benefit of systematic biopsies (detection of ISUP ≥ 2 PCa (clinically significant PCa (csPCa)) solely in systematic biopsies) and fusion failure (detection of csPCa during systematic biopsies in the area of a reported MRI-lesion and no detection of csPCa in targeted biopsy) were compared by growing biopsy experience levels. Multivariable regression analyses were calculated to investigate the association with benefit of systematic biopsies and fusion failure. Results: The overall PCa detection rate was 72% (413/576). A benefit of systematic biopsies was observed in 11% (63/576); of those, fusion failure was seen in 76% (48/63). Benefit of systematic biopsies and fusion failure were more common among residents with very low experience compared to highly experienced residents (18% versus 4%, p = 0.026; 13% versus 3%, p = 0.015, respectively). Increasing biopsy experience was associated with less benefit from systematic biopsies (OR: 0.98, 95% CI 0.97–0.99) and less fusion failure (OR: 0.98, 95% CI 0.97–0.99). Conclusions: The benefit of systematic biopsies following targeted biopsy decreases with growing biopsy experience. The higher risk of fusion failure among inexperienced residents necessitates systematic biopsies to ensure the detection of csPCa. Further prospective trials are warranted before a targeted only approach can be recommended in routine clinical practice.