Reduction of false positives using zone-specific prostate-specific antigen density for prostate MRI-based biopsy decision strategies

Charlie A Hamm; Georg L Baumgärtner; Anwar R Padhani; Konrad P Froböse; Franziska Dräger; Nick L Beetz; Lynn J Savic; Helena Posch; Julian Lenk; Simon Schallenberg; Andreas Maxeiner; Hannes Cash; Karsten Günzel; Bernd Hamm; Patrick Asbach; Tobias Penzkofer

doi:10.1007/s00330-024-10700-z

Reduction of false positives using zone-specific prostate-specific antigen density for prostate MRI-based biopsy decision strategies

Eur Radiol. 2024 Mar 28. doi: 10.1007/s00330-024-10700-z. Online ahead of print.

Authors

Charlie A Hamm^{1

2}, Georg L Baumgärtner³, Anwar R Padhani⁴, Konrad P Froböse³, Franziska Dräger³, Nick L Beetz^{3

5}, Lynn J Savic^{3

5}, Helena Posch³, Julian Lenk³, Simon Schallenberg⁶, Andreas Maxeiner⁷, Hannes Cash⁸, Karsten Günzel⁹, Bernd Hamm³, Patrick Asbach³, Tobias Penzkofer^{3

5}

Affiliations

¹ Department of Radiology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany. Charlie.hamm@charite.de.
² Berlin Institute of Health (BIH), Berlin, Germany. Charlie.hamm@charite.de.
³ Department of Radiology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.
⁴ Paul Strickland Scanner Centre, Mount Vernon Hospital, Northwood, Middlesex, UK.
⁵ Berlin Institute of Health (BIH), Berlin, Germany.
⁶ Institute of Pathology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.
⁷ Department of Urology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.
⁸ Department of Urology, Otto-von-Guericke-University Magdeburg, Germany and PROURO, Berlin, Germany.
⁹ Department of Urology, Vivantes Klinikum Am Urban, Berlin, Germany.

PMID: 38538841
DOI: 10.1007/s00330-024-10700-z

Abstract

Objectives: To develop and test zone-specific prostate-specific antigen density (sPSAD) combined with PI-RADS to guide prostate biopsy decision strategies (BDS).

Methods: This retrospective study included consecutive patients, who underwent prostate MRI and biopsy (01/2012-10/2018). The whole gland and transition zone (TZ) were segmented at MRI using a retrained deep learning system (DLS; nnU-Net) to calculate PSAD and sPSAD, respectively. Additionally, sPSAD and PI-RADS were combined in a BDS, and diagnostic performances to detect Grade Group ≥ 2 (GG ≥ 2) prostate cancer were compared. Patient-based cancer detection using sPSAD was assessed by bootstrapping with 1000 repetitions and reported as area under the curve (AUC). Clinical utility of the BDS was tested in the hold-out test set using decision curve analysis. Statistics included nonparametric DeLong test for AUCs and Fisher-Yates test for remaining performance metrics.

Results: A total of 1604 patients aged 67 (interquartile range, 61-73) with 48% GG ≥ 2 prevalence (774/1604) were evaluated. By employing DLS-based prostate and TZ volumes (DICE coefficients of 0.89 (95% confidence interval, 0.80-0.97) and 0.84 (0.70-0.99)), GG ≥ 2 detection using PSAD was inferior to sPSAD (AUC, 0.71 (0.68-0.74)/0.73 (0.70-0.76); p < 0.001). Combining PI-RADS with sPSAD, GG ≥ 2 detection specificity doubled from 18% (10-20%) to 43% (30-44%; p < 0.001) with similar sensitivity (93% (89-96%)/97% (94-99%); p = 0.052), when biopsies were taken in PI-RADS 4-5 and 3 only if sPSAD was ≥ 0.42 ng/mL/cc as compared to all PI-RADS 3-5 cases. Additionally, using the sPSAD-based BDS, false positives were reduced by 25% (123 (104-142)/165 (146-185); p < 0.001).

Conclusion: Using sPSAD to guide biopsy decisions in PI-RADS 3 lesions can reduce false positives at MRI while maintaining high sensitivity for GG ≥ 2 cancers.

Clinical relevance statement: Transition zone-specific prostate-specific antigen density can improve the accuracy of prostate cancer detection compared to MRI assessments alone, by lowering false-positive cases without significantly missing men with ISUP GG ≥ 2 cancers.

Key points: • Prostate biopsy decision strategies using PI-RADS at MRI are limited by a substantial proportion of false positives, not yielding grade group ≥ 2 prostate cancer. • PI-RADS combined with transition zone (TZ)-specific prostate-specific antigen density (PSAD) decreased the number of unproductive biopsies by 25% compared to PI-RADS only. • TZ-specific PSAD also improved the specificity of MRI-directed biopsies by 9% compared to the whole gland PSAD, while showing identical sensitivity.

Keywords: Clinical decision-making; Image-guided biopsy; Magnetic resonance imaging; Prostate-specific antigen density; Prostatic neoplasms.