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Published on: March 21, 2025
MRI-Derived Restriction Spectrum Imaging Cellularity Index is Associated with High Grade Prostate Cancer on Radical
Michael A Liss1, Nathan S White2, J Kellogg Parsons1
1Department of Urology, University of California San Diego School of Medicine , San Diego, CA , USA.
Purpose:
We evaluate a novel magnetic resonance imaging (MRI) technique to improve detection of aggressive prostate cancer (PCa).
Materials And Methods:
We performed a retrospective analysis of pre-surgical prostate MRI scans using an advanced diffusion-weighted imaging technique called restriction spectrum imaging (RSI), which can be presented as a normalized z-score statistic. Scans were acquired prior to radical prostatectomy. Prostatectomy specimens were processed using whole-mount sectioning and regions of interest (ROIs) were drawn around individual PCa tumors. Corresponding ROIs were drawn on the MRI imaging and paired with ROIs in regions with no pathology. RSI z-score and conventional apparent diffusion coefficient (ADC) values were recorded for each ROI. Paired t-test, ANOVA, and logistic regression analyses were performed.
Results:
We evaluated 28 patients with 64 ROIs (28 benign and 36 PCa). The mean difference in RSI z-score (PCa ROI-Benign ROI) was 2.17 (SE = 0.11; p < 0.001) and in ADC was 551 mm(2)/s (SE = 80 mm(2)/s; paired t-test, p < 0.001). The differences in the means among all groups (benign, primary Gleason 3, and primary Gleason 4) was significant for both RSI z-score (F 3,64 = 97.7, p < 0.001) and ADC (F 3,64 = 13.9, p < 0.001). A t-test was performed on only PCa tumor ROIs (n = 36) to determine PCa aggressiveness (Gleason 3 vs. Gleason 4) revealing that RSI z-score was still significant (p = 0.03), whereas, ADC values were no longer significant (p = 0.08). In multivariable analysis adjusting for age and race, RSI z-score was associated with PCa aggressiveness (OR 10.3, 95% CI: 1.4-78.0, p = 0.02) while ADC trended to significance (p = 0.07).
Conclusion:
The RSI-derived normalized cellularity index is associated with aggressive PCa as determined by pathologic Gleason scores. Further utilization of RSI techniques may serve to enhance standardized reporting systems for PCa in the future.
Insights
Restriction spectrum imaging (RSI) shows promise in detecting aggressive prostate cancer (PCa). This advanced MRI technique, measuring normalized cellularity, correlates with higher Gleason scores, aiding in PCa diagnosis.
Area of Science:
- Oncology
- Radiology
- Medical Imaging
Background:
- Accurate detection of aggressive prostate cancer (PCa) is crucial for effective treatment planning.
- Conventional MRI techniques may have limitations in differentiating indolent from aggressive PCa.
- Novel imaging biomarkers are needed to improve diagnostic accuracy.
Purpose of the Study:
- To evaluate a novel magnetic resonance imaging (MRI) technique, restriction spectrum imaging (RSI), for improved detection of aggressive prostate cancer (PCa).
- To assess the association between RSI-derived metrics and pathological Gleason scores in PCa.
Main Methods:
- Retrospective analysis of pre-surgical prostate MRI scans from 28 patients using restriction spectrum imaging (RSI).
- Regions of interest (ROIs) were drawn on whole-mount prostatectomy specimens and corresponding MRI images.
- RSI z-scores and apparent diffusion coefficient (ADC) values were recorded and statistically analyzed.
Main Results:
- RSI z-scores significantly differed between benign and PCa ROIs (p < 0.001) and were also significant in differentiating Gleason 3 from Gleason 4 tumors (p = 0.03).
- ADC values showed significant differences between benign and PCa ROIs (p < 0.001) but did not significantly differentiate Gleason 3 from Gleason 4 tumors (p = 0.08).
- In multivariable analysis, RSI z-score was significantly associated with PCa aggressiveness (OR 10.3, p = 0.02).
Conclusions:
- The RSI-derived normalized cellularity index is associated with aggressive PCa, as confirmed by pathological Gleason scores.
- RSI demonstrates potential as a valuable tool for enhancing standardized reporting systems for prostate cancer.
- Further research into RSI techniques may improve the non-invasive characterization of PCa aggressiveness.
