Pathologic prostate cancer grade concordance among high-resolution micro-ultrasound, systematic transrectal ultrasound and MRI fusion biopsy.

Background and objective: Comparative studies among biopsy strategies have not been conducted evaluating pathologic concordance at radical prostatectomy(RP), especially with novel micro-ultrasound (micro-US) image-guided biopsy.

Methods: A retrospective study among patients with PCa who underwent RP following TRUS, MRI-TRUS fusion, microUS, or MRI-microUS fusion biopsy in a multi-site single institution. We compared GG-upgrade from biopsy to RP based on highest GG in any biopsy core and examined clinical/pathologic factors associated with pathologic upgrading using descriptive statistics, and multivariable logistic-regression analysis.

Results: 429 patients between 1/2021 and 6/2023 including 10 (25.6%) who underwent systematic TRUS, 237 (55.2%) MRI-TRUS, 67 (15.6%) MRI-microUS and 15 (3.5%) micoUS-alone biopsy prior to RP. 78 (18.2%) were upgraded on final pathology (TRUS 31 (28.2%), MRI-TRUS 31 (13.1%), MRI-microUS 10 (14.9%), microUS: 6 (40%)) and 99 downgraded. 14 (3.5%) experienced a major upgrade (≥2 GG increase). On multivariable-analysis both MRI-TRUS (odds ratio, OR: 0.31,95% CI:0.17-0.56, P < 0.001) and MRI-microUS (OR: 0.43,95%CI: 0.19-0.98, P = 0.044) were associated with lower odds pathological-upgrade compared with TRUS biopsy alone. No significant differences in the odds of upgrade between TRUS and microUS alone (P > 0.05), or between MRI-microUS and MRI-TRUS(P = 0.696) on pairwise comparisons. MRI-microUS was associated with lower upgrade compared with microUS (OR: 0.26,95% CI:0.08-0.90, P = 0.034). No difference among the biopsy strategies in pathologic downgrading or overall GG concordance. Limitations include retrospective analysis, inter-clinician experience and lesion selection in varying biopsy techniques.

Conclusion: Both MRI-microUS and MRI-TRUS fusion were associated with similarly improved GG concordance compared with TRUS biopsy. No significant differences between microUS-alone and TRUS or between MRI-microUS and MRI-TRUS fusion approaches, may suggest similar accuracy performance for disease sampling.

What does the study add: To our knowledge, this is the first study to investigate GG concordance based on type of biopsy, especially microUS related GG upgrading after RP. In a moderately sized cohort this is the first to investigate pathologic concordance in MRI-microUS fusion compared to MRI-TRUS fusion biopsy. Our study may help urologists in counseling patients after biopsy and choosing the ideal image guided biopsy technique, however randomized controlled trials are needed to validate our results.

Patient summary: We performed a study to see if the type of prostate biopsy, including use of MRI assistance as well as a new image-guided biopsy using a more advanced ultrasound, was better able to identify the aggressiveness of prostate cancer patients had. We found that the new biopsy type when fused with MRI and the existing MRI-guided biopsy type were similar in predicting the type of prostate cancer found at prostate surgery. These were both more accurate than the conventional ultrasound only biopsy.