A study published in JAMA Oncology investigated the role of multi-parametric MRI in prostate cancer (PCa) diagnosis, particularly in patients identified through screening. The findings indicate that MRI can reduce unnecessary biopsies, decrease clinically insignificant disease detection, and improve the likelihood of diagnosing PCa. The benefits of MRI include avoiding contrast use, shorter exams, lower costs, and reduced risk of adverse events, which offer potential economic advantages for healthcare systems.
In the PRIME study, the results showed that 2 patients had clinically significant PCa (defined as Gleason Grade Group 2 or greater), which was missed by biparametric MRI. However, biparametric MRI did not detect additional clinically significant PCa compared to multi-parametric MRI and missed two patients with such cancer. Most scans were upgraded from a Likert score of 1 or 2 on biparametric MRI to 3 or 4 on multi-parametric MRI. The proportion of men with a Likert score of 3 or higher was 57%, similar to biparametric and multi-parametric MRI. Notably, the proportion of men with a Likert score of 3, indicating uncertainty about clinically significant PCa, was as low as 15%.
In the PROMIS trial, the role of multi-parametric MRI and biparametric MRI in detecting clinically significant PCa was evaluated. However, the PROMIS trial utilized different methods, including transperineal prostate mapping. The rate of equivocal lesions was higher in the PROMIS trial compared to the PRIME study (30% vs. 28%). Additionally, the addition of dynamic contrast enhancement (DCE) did not significantly improve the detection of clinically significant PCa in this trial. Notably, DCE's primary role was observed in PI-RADS 3 lesions, and all patients with a Likert or PI-RADS score of 3 or higher underwent biopsy. The use of DCE is recommended when other sequences are of insufficient diagnostic quality, emphasizing its adjunctive role in specific circumstances.
The PRIME trial emphasizes relying on high-quality MRI, specifically biparametric MRI, for PCa diagnosis. Approximately 95% of patients in the trial had MRIs of PI-QUAL 4 or 5, achieved through quality control measures and centralized image review. In total, 41 centres provided 355 multi-parametric MRI (mpMRI) studies from 71 scanners. Among these, 9 scanners (13%) scored a 3 on the PI-QUAL scale, 39 (55%) scored a 4, and 23 (32%) scored a 5. Feedback was given to 48 scanners (68%) for improvement, with DCE sequences showing the least adherence to PI-RADS criteria (92%), followed by diffusion-weighted imaging (42%) and T2-weighted imaging (40%). In phase II, 36 centres from 17 countries resubmitted revised studies, resulting in 62 scanners (97%) achieving a final PI-QUAL score of 5.
In conclusion, implementing biparametric MRI does not reduce the likelihood of diagnosing clinically significant PCa but increases MRI usage, thereby addressing global MRI availability shortages. This approach also decreases acquisition time and costs per exam. The role of DCE in specific scenarios like margin delineation, planning for focal therapy, or post-treatment evaluation remains uncertain.
European Association of Urology (EAU) Annual Congress 2024, 5th April - 8th April 2024, Paris, France
