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Updated: Dec 6, 2025
A Cognitive Fusion-guided Prostate Biopsy Using Multiparametric Magnetic Resonance Imaging and Transrectal Ultrasound
Published on: March 21, 2025
Multiparametric magnetic resonance imaging facilitates reclassification during active surveillance for prostate
Atsuko Fujihara1,2, Tsuyoshi Iwata1,2, Aliasger Shakir1
1USC Institute of Urology and Catherine & Joseph Aresty Department of Urology, University of Southern California, Los Angeles, CA, USA.
Objective:
To investigate the utility of multiparametric magnetic resonance imaging (mpMRI) in the reassessment and monitoring of patients on active surveillance (AS) for Grade Group (GG) 1 prostate cancer (PCa).
Patients And Methods:
We identified, from our prospectively maintained institutional review board-approved database, 181 consecutive men enrolled on AS for GG 1 PCa who underwent at least one surveillance mpMRI followed by MRI/prostate biopsy (PBx). A subset analysis was performed among 68 patients who underwent serial (at least two) mpMRI/PBx during AS. Pathological progression (PP) was defined as upgrade to GG ≥2 on follow up biopsy.
Results:
Baseline MRI was performed in 34 patients (19%). At a median follow-up of 2.2 years for the overall cohort, the PP was 12% (6/49) for Prostate Imaging Reporting and Data System (PI-RADS) 1-2 lesions and 37% (48/129) for the PI-RADS ≥3 lesions. The 2-year PP-free survival rate was 84%. Surveillance prostate-specific antigen density (P < 0.001) and surveillance PI-RADS ≥3 (P = 0.002) were independent predictors of PP on reassessment MRI/PBx. In the serial MRI cohort, the 2-year PP-free survival was 95% for the No-MRI-progression group vs 85% for the MRI-progression group (P = 0.02). MRI progression was significantly higher in the PP (62%) than in the No-PP (31%) group (P = 0.04). If serial MRI were used for PCa surveillance and biopsy were triggered based only on MRI progression, 63% of PBx might be postponed at the cost of missing 12% of GG ≥2 PCa in those with stable MRI. Conversely, this strategy would miss 38% of those with upgrading to GG ≥2 PCa on biopsy. Stable serial mpMRI correlates with no reclassification to GG ≥3 PCa during AS.
Conclusion:
On surveillance mpMRI, PI-RADS ≥3 was associated with increased risk of PCa reclassification. Surveillance biopsy based only on MRI progression may avoid a large number of biopsies at the cost of missing many PCa reclassifications.
Insights
Multiparametric MRI (mpMRI) helps monitor Grade Group 1 prostate cancer (PCa) during active surveillance. Lesions with higher PI-RADS scores indicate a greater risk of progression, but relying solely on MRI for biopsy decisions may miss some cancer upgrades.
Area of Science:
- Urology
- Radiology
- Oncology
Background:
- Active surveillance (AS) is a management strategy for low-risk prostate cancer (PCa).
- Multiparametric magnetic resonance imaging (mpMRI) is increasingly used in PCa assessment.
- Monitoring treatment response and disease progression is crucial in AS.
Purpose of the Study:
- To evaluate the effectiveness of mpMRI in reassessing and monitoring patients with Grade Group (GG) 1 PCa undergoing AS.
- To determine the correlation between mpMRI findings and pathological progression (PP) on biopsy.
- To assess the potential impact of using MRI progression as a trigger for biopsy during AS.
Main Methods:
- Retrospective analysis of 181 patients with GG 1 PCa on AS, with at least one surveillance mpMRI and subsequent prostate biopsy (PBx).
- Subset analysis of 68 patients with serial mpMRI/PBx.
- Pathological progression defined as upgrade to GG ≥2 on follow-up biopsy.
Main Results:
- 12% progression for PI-RADS 1-2 lesions vs. 37% for PI-RADS ≥3 lesions.
- The 2-year progression-free survival rate was 84%.
- Surveillance prostate-specific antigen density and PI-RADS ≥3 were independent predictors of PP.
- In serial MRI cohort, 2-year progression-free survival was 95% for no MRI progression vs. 85% for MRI progression (P=0.02).
- MRI progression was significantly higher in the PP group (62%) than in the no-PP group (31%).
Conclusions:
- Higher PI-RADS scores (≥3) on surveillance mpMRI are associated with an increased risk of PCa reclassification.
- Using MRI progression alone to trigger biopsies could postpone many procedures but might miss some cases of significant PCa upgrading.
- Stable serial mpMRI findings correlate with no reclassification to higher Grade Groups during active surveillance.
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