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A Cognitive Fusion-guided Prostate Biopsy Using Multiparametric Magnetic Resonance Imaging and Transrectal Ultrasound
Published on: March 21, 2025
Natural history of prostatic lesions on serial multiparametric magnetic resonance imaging
Samrad Ghavimi1, Hamidreza Abdi1, Jennifer Waterhouse2
1Department of Urologic Sciences, University of British Columbia, Vancouver, BC, Canada.
Introduction:
The natural history of prostatic lesions identified on multiparametric magnetic resonance imaging (mpMRI) is largely unknown. We aimed to describe changes observed over time on serial MRI.
Methods:
All patients with ≥2 MRI studies between 2008 and 2015 at our institution were identified. MRI progression was defined as an increase in Prostate Imaging Reporting and Data System (PI-RADS; version 2) or size of existing lesions, or the appearance of a new lesion PIRADS ≥4. Patients on active surveillance (AS) were analyzed for correlation of MRI progression to biopsy reclassification.
Results:
A total of 83 patients (54 on AS and 29 for diagnostic purposes) underwent serial MRI, with a mean interval of 1.9 years between scans. At baseline, 115 lesions (66 index, 49 non-index) were identified. Index lesions were more likely than non-index lesions to increase in size ≥2 mm (36.2 vs. 7.3 %; p=0.002). Overall progression was more likely to be seen among the index cohort (34.8 vs. 7.6%; p<0.001). New lesions with PI-RADS ≥4 were seen on second imaging in 13 (16.5%) men, and became the index lesion in 29 cases (34.9%). Eighteen men on AS showed evidence of MRI progression (five with new lesions, 13 with progression of a previous lesion). Biopsy reclassification was present in three men (16.7%) with and seven men without MRI progression (19.4%).
Conclusions:
Overall changes in size and PI-RADS scores of index lesions on MRI were small. New lesions were common, but usually did not alter management.
Insights
Serial multiparametric MRI (mpMRI) shows that while new prostate lesions are common, index lesions typically show minimal changes. This natural history insight is crucial for understanding prostate cancer progression on MRI.
Area of Science:
- Radiology
- Oncology
- Urology
Background:
- The natural history of prostatic lesions detected by multiparametric MRI (mpMRI) is not well understood.
- Serial imaging is essential for characterizing lesion behavior over time.
Purpose of the Study:
- To describe the temporal changes in prostatic lesions identified on serial mpMRI.
- To evaluate the correlation between MRI progression and biopsy reclassification in patients on active surveillance.
Main Methods:
- Retrospective analysis of 83 patients with at least two mpMRI scans between 2008 and 2015.
- MRI progression defined by PI-RADS score increase, lesion size increase, or new PI-RADS ≥4 lesions.
- Analysis of biopsy reclassification in patients on active surveillance with MRI progression.
Main Results:
- Index lesions were more likely to increase in size (36.2%) and show overall progression (34.8%) compared to non-index lesions.
- New PI-RADS ≥4 lesions were observed in 16.5% of patients, becoming the index lesion in 34.9% of cases.
- MRI progression occurred in 18 men on active surveillance, but biopsy reclassification rates were similar with (16.7%) and without (19.4%) MRI progression.
Conclusions:
- Prostate lesion size and PI-RADS scores show small changes on serial mpMRI.
- New lesions are frequently identified but typically do not necessitate changes in patient management.
- Understanding the natural history of mpMRI findings aids in active surveillance strategies.
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