Introduction: Prostate cancer localization is essential before performing focal therapy. We analyzed the concordance between MRIs, systematic and targeted biopsies, and whole prostate gland removals with the aim of half-gland treatment.
Materials and methods: Between 2016 and 2022, we analyzed 132 patients who benefited from positive MRIs (i.e. PI-RADS≥3), biopsies (ISUP 2-3) and radical prostatectomies (RP). MRIs were performed in any imaging office, without double reading. Biopsies were taken after MRI/US fusion by prostate cancer specialist urologists. The hemi-gland of significant prostate cancer localization was collected on MRIs (PI-RADS), biopsies (ISUP) and prostatectomies. Concordance analyses and predictive values were calculated between MRIs and biopsies, MRIs and RPs, biopsies and RPs, and in the concordant MRI/biopsy and RP population. ISUP 1 was considered as negative.
Results: Concordance rates vary from 74.24% to 85.05%; Kappa's ratio from 0.42 to 0.65. Neither MRIs nor biopsies detect a significant prostate locus in 24% of cases. PPVs and NPVs for MRIs/biopsies and prostatectomies are 99% and 51.5%, respectively. Grading prediction is accurate in 85% of cases.
Discussion: The concordance rate is moderate with NPVs synonymous with the risk of undertreatment. The absence of MRI target (but with significant carcinoma after RPs) is a key part of this risk but not always corrected with systematic standard biopsies. Targeted biopsies confirm the MRI foci.
Conclusion: Due to significant cancer in negative MRI areas, the selection method before focal therapy, i.e. half-gland treatment, may be improved and underlines the importance of systematic biopsies.
Keywords: Biopsie; Biopsy; Cancer de la prostate; Focal therapy; IRM de la prostate; Multiparametric magnetic resonance imaging; Prostate cancer; Prostatectomie; Prostatectomy; Traitement focal.
Copyright © 2025. Published by Elsevier Masson SAS.