Multiparametric Magnetic Resonance Imaging-targeted Prostate Biopsy: A Plea for a Change in Terminology, and Beyond

Optimizing multiparametric magnetic resonance imaging-targeted biopsy and prostate cancer grading accuracy

PURPOSE

To assess the most efficient biopsy method to improve International Society of Urological Pathology (ISUP) grade group accuracy with final pathology of the radical prostatectomy (RP) specimen in the era of magnetic resonance imaging (MRI)-driven pathway.

METHODS

A total of 753 patients diagnosed by transrectal MRI-targeted and systematic biopsies (namely "standard method"), treated by RP, between 2016 and 2021 were evaluated. Biopsy methods included MRI-targeted biopsy, side-specific systematic biopsies relative to index MRI lesion and combination of both. Number of MRI-targeted biopsy cores and positive cores needed per index MRI lesion were assessed. Multivariable analysis was performed to analyze predictive factors of upgrading using MRI targeted and ipsilateral systematic biopsies method.

RESULTS

Overall, ISUP grade group accuracy varied among biopsy methods with upgrading rate of 35%, 49%, 27%, and 24% for MRI targeted, systematic, MRI targeted and ipsilateral systematic biopsies and standard methods, respectively (p < 0.001). A minimum of two positive MRI-targeted biopsies cores per index MRI lesion were required when testing MRI targeted and ipsilateral systematic biopsies method to reach equivalent accuracy compared to standard method. Omitting contralateral systematic biopsies spared an average of 5.9 cores per patient. At multivariable analysis, only the number of positive MRI-targeted biopsy cores per index MRI lesion was predictive of upgrading.

CONCLUSION

MRI targeted and ipsilateral systematic biopsies allowed an accurate definition of ISUP grade group and appears to be an interesting alternative when compared with standard method, reducing total number of biopsy cores needed.

The role of perilesional and multiparametric resonance imaging-targeted biopsies to reduce the risk of upgrading at radical prostatectomy pathology: A retrospective monocentric study

PURPOSE

To evaluate histopathologic upgrading between biopsy methods and whole-mount prostatectomy specimens in International Society of Urological Pathology grade group.

METHODS

Overall, 134 patients, including 175 magnetic resonance imaging (MRI)-suspicious lesions, diagnosed on MRI-targeted (TB) and systematic (SB) biopsies before radical prostatectomy were retrospectively analyzed from a prospectively maintained database. Perilesional (PLB) and "extended" perilesional (ePLB) biopsies were defined as those taken within a circumferential zone of 5 and 10 mm around magnetic resonance imaging (MRI)-suspicious lesion respectively. Proportion of upgrading at prostatectomy pathology were compared between TB, TB + PLB, TP + ePLB and TB + SB. Uni- and multivariable logistic regressions assessed predictors of upgrading for TB + ePLB method.

RESULTS

Focusing on index lesion, median (interquartile range) number of cores taken was 4 (3-4) for TB, 5 (4-6) for TB + PLB, 6 (5-8) for TB + ePLB and 12 (12-15) for TB + SB. A higher upgrading proportion was detected upon comparing TB and TB + PLB methods to TB + SB (32 vs. 19%, P = 0.001, 26 vs. 19%, P = 0.04, respectively). Conversely, no significant difference was found between TB + ePLB compared to TB + SB (23 vs. 19%, P = 0.2). Proportion of downgrading was similar regardless of biopsy method (all P > 0.1). At multivariable analysis, Prostate Imaging-Reporting and Data System Steering score, total number of positive ePLB cores and International Society of Urological Pathology Grade Group were independent predictors of upgrading (all P ≤ 0.03). Similar results were found by adding data from non-index lesions.

CONCLUSION

Our finding suggest that MRI-targeted biopsies associated with perilesional sampling in a circumferential zone of 10 mm reduced upgrading proportion and showed similar accuracy as the current gold standard combination. Further prospective studies comparing biopsy methods are expected to validate this diagnostic strategy.

Limitations of overlapping cores in systematic and MRI-US fusion biopsy

OBJECTIVES

To evaluate the clinically-significant prostate cancer (csCaP) detection rate of systematic (SBx) vs. targeted biopsy (TBx), after accounting for the overlapping systematic cores within the MRI regions of interest.

MATERIALS AND METHODS

We identified 398 consecutive men who underwent both transperineal systematic and targeted biopsy between January 2015 to January 2019. We reclassified overlapping systematic cores in the MRI regions of interest as target cores. The detection rates of SBx and TBx were compared using McNemar's test.

RESULTS

Detection rate of csCaP (grade group ≥2) was 42% (168/398). Median number of systematic and targeted cores were 23 (IQR 19-29) and 9 (IQR 6-12) respectively. A median of 3 (IQR 2-4) overlapping systematic cores were reclassified as targeted cores. After accounting for overlap, csPC detection rate on SBx decreased from 37% and 21% while the csCaP detection rate of TBx increased from 34% to 39% (both P < 0.001), with TBx having a better detection rate (39% vs. 21%, P < 0.001). A previous negative biopsy was associated with a lower risk of having csCaP on non-targeted SBx (OR 0.27, 95% CI: 0.12 - 0.58, P = 0.001). Only 5% (13/243) of those who had no cancer detected on TBx had csCaP on non-targeted SBx compared to 45% (70/155) of those who had csCaP on TBx (P< 0.001).

CONCLUSIONS

The utility of SBx in detecting csCaP decreases after accounting for overlap into the MRI region of interest, especially in men with a prior negative biopsy. Overlapping systematic cores improve the csCaP detection rate on TBx.