Comparative Analysis of Biparametric vs Multiparametric MRI for Prostate Assessment

Overview

This study compared biparametric MRI (bpMRI) and multiparametric MRI (mpMRI) using PI-RADS v2.1 scoring for detecting prostate cancer (PCa) and clinically significant PCa (csPCa) in biopsy-naïve men with elevated PSA. Both imaging protocols were evaluated against histopathology from robot-assisted transperineal fusion biopsy (RA-TB). The findings suggest comparable diagnostic performance between bpMRI and mpMRI in this clinical setting.

Background

Prostate cancer is the most common non-cutaneous cancer in men, with a lifetime risk up to 37%. Multiparametric MRI (mpMRI), including T2-weighted imaging, diffusion-weighted imaging, and dynamic contrast-enhanced imaging (DCE), is the current standard for prostate evaluation using PI-RADS v2.1. However, the role of DCE remains controversial, and biparametric MRI (bpMRI), which omits DCE, offers advantages such as reduced cost, shorter scan time, and avoidance of contrast agent risks. Differentiating PCa from benign conditions like chronic prostatitis is challenging, especially in PI-RADS 3 lesions, where histology often reveals inflammation.

Data Highlights

Key Findings

• Both bpMRI and mpMRI showed substantial inter-reader agreement for PI-RADS v2.1 scoring.
• In PI-RADS 3 lesions, mpMRI upgraded some lesions to PI-RADS 4 based on DCE, but no reader differences were observed in these cases.
• Histopathology from robot-assisted transperineal fusion biopsy served as the reference standard for cancer detection.
• bpMRI demonstrated similar sensitivity and specificity to mpMRI for detecting PCa and csPCa in biopsy-naïve men with elevated PSA.
• The omission of DCE in bpMRI did not significantly reduce diagnostic accuracy compared to mpMRI.

Clinical Implications

Biparametric MRI may serve as a reliable alternative to multiparametric MRI for prostate cancer detection, offering advantages such as shorter scan times and avoidance of contrast-related risks. This supports consideration of bpMRI in routine clinical protocols, especially for biopsy-naïve patients with elevated PSA. However, careful interpretation remains essential, particularly in PI-RADS 3 lesions where differentiation from benign conditions is challenging.

Conclusion

The study supports that bpMRI provides comparable diagnostic performance to mpMRI for prostate cancer detection prior to robot-assisted transperineal fusion biopsy. This suggests bpMRI could be a cost-effective and safer imaging alternative without compromising accuracy.

References

1. Weinreb et al. 2016 -- PI-RADS v2.1: Prostate Imaging Reporting and Data System
2. European Society of Urogenital Radiology Guidelines
3. Rosenkrantz et al. 2019 -- Diagnostic Accuracy of bpMRI vs mpMRI
4. R Core Team 2021 -- R: A language and environment for statistical computing