A multicentric study on accurate grading of prostate cancer with systematic and MRI/US fusion targeted biopsies: comparison with final histopathology after radical prostatectomy

Objective To evaluate the accuracy in histologic grading of MRI/US image fusion biopsy by comparing histopathology between systematic biopsies (SB), targeted biopsies (TB) and the combination of both (SB + TB) with the final histopathologic outcomes of radical prostatectomy specimens.Materials and methods Retrospective, multicentric study of 443 patients who underwent SB and TB using MRI/US fusion technique-(Urostation (R) and-Trinity (R)) prior to radical prostatectomy between 2010 and 2017. Cochran's Q test and McNemar test were conducted as a post hoc test. Uni-multivariable analyses were performed on several clinic-pathological variables to analyze factors predicting histopathological concordance for targeted biopsies.Results Concordance in ISUP (International Society of Urological Pathology) grade between SB, TB and SB + TB with final histopathology was 49.4%, 51.2%, and 63.2% for overall prostate cancer and 41.2%, 48.3%, and 56.7% for significant prostate cancer ( ISUP grade = 2), respectively. Significant difference in terms of concordance, downgrading and upgrading was found between SB and TB (ISUP grade = 2 only), SB and SB + TB, TB and SB + TB (overall ISUP grade and ISUP grade >= 2) (p < 0.001). Total number of cores and previous biopsies were significant independent predictive factors for concordance with TB technique.Conclusion In this retrospective study, combination of SB and TB significantly increased concordance with final histopathology despite a limited additional number of cores needed.