MRI-based Deep Learning Algorithm for Assisting Clinically Significant Prostate Cancer Detection: A Bicenter Prospective Study
Abstract
A commercial MRI-based deep learning algorithm for prostate cancer detection showed greater positive predictive value, despite its lower sensitivity, potentially allowing it to assist radiologists in biopsy planning.
Background
Although artificial intelligence is actively being developed for prostate MRI, few studies have prospectively validated these tools.
Purpose
To compare the diagnostic performance of a commercial deep learning algorithm (DLA) and radiologists’ clinical reports for cancer detection in participants from two hospitals using histopathologic findings from biopsy specimens as the reference standard.
Materials and Methods
This prospective bicenter study enrolled participants suspected of having prostate cancer (PCa) who were scheduled for biopsy based on clinical information, including prostate MRI, from December 2022 to July 2023. Targeted prostate biopsies were performed for lesions with Prostate Imaging Reporting and Data System (PI-RADS) scores of 3 or higher, identified by either radiologists or the DLA. PI-RADS classifications by radiologists (using all imaging sequences), the DLA (using biparametric MRI), and the scenario in which radiologist-based PI-RADS 3 scores were modulated with DLA-based PI-RADS scores were compared using the area under the receiver operating characteristic curve (AUC) with DeLong and McNemar tests.
Results
A total of 259 lesions, including 117 clinically significant PCas (csPCas) (Gleason grade group ≥2), were evaluated in 205 men (median age, 68 years; age range, 47–90 years). At per-lesion analysis, the DLA had a lower sensitivity (94 of 117; 80%) and higher positive predictive value (PPV) (94 of 163; 58%) for detecting csPCa than did the radiologists (109 of 117 [93%] and 109 of 227 [48%]; P = .02 and P = .008, respectively). At per-participant analysis, incorporation of the DLA increased specificity from 23 of 108 (21%) to 48 of 108 (44%) (P = .001), with similar sensitivity (96 of 97 [99%] vs 93 of 97 [96%]; P = .74). There was no evidence of a difference in the AUC between radiologist-based and DLA-based PI-RADS score (0.77 [95% CI: 0.70, 0.82] vs 0.79 [95% CI: 0.73, 0.85]; P = .73).
Conclusion
The DLA demonstrated lower sensitivity but a greater PPV than radiologists for detecting csPCa in a biopsy setting. Using DLA results when radiologists’ interpretations are indeterminate could improve specificity while maintaining sensitivity.
International Clinical Trials Registry Platform registration no. KCT0006947
© RSNA, 2025
References
- 1. . Use of prostate systematic and targeted biopsy on the basis of multiparametric MRI in biopsy-naive patients (MRI-FIRST): a prospective, multicentre, paired diagnostic study. Lancet Oncol 2019;20(1):100–109.
- 2. . MRI-Targeted or Standard Biopsy for Prostate-Cancer Diagnosis. N Engl J Med 2018;378(19):1767–1777.
- 3. . Diagnostic accuracy of multi-parametric MRI and TRUS biopsy in prostate cancer (PROMIS): a paired validating confirmatory study. Lancet 2017;389(10071):815–822.
- 4. . Paradigm Shift in Prostate Cancer Diagnosis: Pre-Biopsy Prostate Magnetic Resonance Imaging and Targeted Biopsy. Korean J Radiol 2022;23(6):625–637.
- 5. . Comparison of Multiparametric Magnetic Resonance Imaging-Targeted Biopsy With Systematic Transrectal Ultrasonography Biopsy for Biopsy-Naive Men at Risk for Prostate Cancer: A Phase 3 Randomized Clinical Trial. JAMA Oncol 2021;7(4):534–542.
- 6. . Which Patients with Negative Magnetic Resonance Imaging Can Safely Avoid Biopsy for Prostate Cancer? J Urol 2019;201(2):268–276.
- 7. . Prostate Imaging Reporting and Data System Version 2.1: 2019 Update of Prostate Imaging Reporting and Data System Version 2. Eur Urol 2019;76(3):340–351.
- 8. . Prostate cancer detection with biparametric magnetic resonance imaging (bpMRI) by readers with different experience: performance and comparison with multiparametric (mpMRI). Abdom Radiol (NY) 2019;44(5):1883–1893.
- 9. . Interreader Variability of Prostate Imaging Reporting and Data System Version 2 in Detecting and Assessing Prostate Cancer Lesions at Prostate MRI. AJR Am J Roentgenol 2019;212(6):1197–1205.
- 10. . Factors Influencing Variability in the Performance of Multiparametric Magnetic Resonance Imaging in Detecting Clinically Significant Prostate Cancer: A Systematic Literature Review. Eur Urol Oncol 2020;3(2):145–167.
- 11. . Positive Predictive Value of Prostate Imaging Reporting and Data System Version 2 for the Detection of Clinically Significant Prostate Cancer: A Systematic Review and Meta-analysis. Eur Urol Oncol 2021;4(5):697–713.
- 12. . Variability of the Positive Predictive Value of PI-RADS for Prostate MRI across 26 Centers: Experience of the Society of Abdominal Radiology Prostate Cancer Disease-focused Panel. Radiology 2020;296(1):76–84.
- 13. . Artificial intelligence for prostate MRI: open datasets, available applications, and grand challenges. Eur Radiol Exp 2022;6(1):35.
- 14. . Artificial intelligence algorithms aimed at characterizing or detecting prostate cancer on MRI: How accurate are they when tested on independent cohorts? - A systematic review. Diagn Interv Imaging 2023;104(5):221–234.
- 15. . A concurrent, deep learning-based computer-aided detection system for prostate multiparametric MRI: a performance study involving experienced and less-experienced radiologists. Eur Radiol 2023;33(1):64–76.
- 16. . Interactive Explainable Deep Learning Model Informs Prostate Cancer Diagnosis at MRI. Radiology 2023;307(4):e222276.
- 17. . Classification of Cancer at Prostate MRI: Deep Learning versus Clinical PI-RADS Assessment. Radiology 2019;293(3):607–617.
- 18. . Deep-Learning-Based Artificial Intelligence for PI-RADS Classification to Assist Multiparametric Prostate MRI Interpretation: A Development Study. J Magn Reson Imaging 2020;52(5):1499–1507.
- 19. . Detection and PI-RADS classification of focal lesions in prostate MRI: Performance comparison between a deep learning-based algorithm (DLA) and radiologists with various levels of experience. Eur J Radiol 2021;142:109894.
- 20. . Artificial intelligence and radiologists in prostate cancer detection on MRI (PI-CAI): an international, paired, non-inferiority, confirmatory study. Lancet Oncol 2024;25(7):879–887.
- 21. . Machine learning for the identification of clinically significant prostate cancer on MRI: a meta-analysis. Eur Radiol 2020;30(12):6877–6887.
- 22. . A Novel Deep Learning Based Computer-Aided Diagnosis System Improves the Accuracy and Efficiency of Radiologists in Reading Biparametric Magnetic Resonance Images of the Prostate: Results of a Multireader, Multicase Study. Invest Radiol 2021;56(10):605–613.
- 23. PASS 2021 Power Analysis and Sample Size Software. NCSS, LLC. https://www.ncss.com/software/pass/. Published 2021. Accessed June 5, 2023.
- 24. . MRI in early prostate cancer detection: how to manage indeterminate or equivocal PI-RADS 3 lesions? Transl Androl Urol 2018;7(1):70–82.
- 25. . PI-RADS 3 score: A retrospective experience of clinically significant prostate cancer detection. BJUI Compass 2023;4(4):473–481.
- 26. . Artificial Intelligence for Automated Cancer Detection on Prostate MRI: Opportunities and Ongoing Challenges, From the AJR Special Series on AI Applications. AJR Am J Roentgenol 2022;219(2):188–194.
- 27. . Clinically significant prostate cancer detection and segmentation in low-risk patients using a convolutional neural network on multi-parametric MRI. Eur Radiol 2020;30(12):6582–6592.
- 28. . Simulated clinical deployment of fully automatic deep learning for clinical prostate MRI assessment. Eur Radiol 2021;31(1):302–313.
- 29. . Effect of Prostate MRI Interpretation Experience on PPV Using PI-RADS Version 2: A 6-Year Assessment Among Eight Fellowship-Trained Radiologists. AJR Am J Roentgenol 2022;219(3):453–460.
- 30. . Comparison of biopsy strategies for prostate biopsy according to lesion size and PSA density in MRI-directed biopsy pathway. Abdom Radiol (NY) 2020;45(12):4166–4177.
- 31. . Interreader Agreement with Prostate Imaging Reporting and Data System Version 2 for Prostate Cancer Detection: A Systematic Review and Meta-Analysis. J Urol 2020;204(4):661–670.
- 32. . Cancer detection rates of the PI-RADSv2.1 assessment categories: systematic review and meta-analysis on lesion level and patient level. Prostate Cancer Prostatic Dis 2022;25(2):256–263.
- 33. . Current status of magnetic resonance imaging (MRI) and ultrasonography fusion software platforms for guidance of prostate biopsies. BJU Int 2014;114(5):641–652.
- 34. . Prostate Imaging Quality (PI-QUAL): A New Quality Control Scoring System for Multiparametric Magnetic Resonance Imaging of the Prostate from the PRECISION trial. Eur Urol Oncol 2020;3(5):615–619.
Article History
Received: Oct 19 2023Revision requested: Dec 13 2023
Revision received: Jan 8 2025
Accepted: Feb 3 2025
Published online: Mar 11 2025