Magnetic resonance imaging-ultrasound fusion biopsy for prediction of final prostate pathology

The impact of mpMRI-targeted vs systematic biopsy on the risk of prostate cancer downgrading at final pathology

PURPOSE

Although targeted biopsies (TBx) are associated with improved disease assessment, concerns have been raised regarding the risk of prostate cancer (PCa) overgrading due to more accurate biopsy core deployment in the index lesion.

METHODS

We identified 1672 patients treated with radical prostatectomy (RP) with a positive mpMRI and ISUP ≥ 2 PCa detected via systematic biopsy (SBx) plus TBx. We compared downgrading rates at RP (ISUP 4-5, 3, and 2 at biopsy, to a lower ISUP) for PCa detected via SBx only (group 1), via TBx only (group 2), and eventually for PCa detected with the same ISUP 2-5 at both SBx and TBx (group 3), using multivariable logistic regression models (MVA).

RESULTS

Overall, 12 vs 14 vs 6% (n = 176 vs 227 vs 96) downgrading rates were recorded in group 1 vs group 2 vs group 3, respectively (p < 0.001). At MVA, group 2 was more likely to be downgraded (OR 1.26, p = 0.04), as compared to group 1. Conversely, group 3 was less likely to be downgraded at RP (OR 0.42, p < 0.001).

CONCLUSIONS

Downgrading rates are highest when PCa is present in TBx only and, especially when the highest grade PCa is diagnosed by TBx cores only. Conversely, downgrading rates are lowest when PCa is identified with the same ISUP through both SBx and TBx. The presence of clinically significant disease at SBx + TBx may indicate a more reliable assessment of the disease at the time of biopsy potentially reducing the risk of downgrading at final pathology.

A radiomics based method for prediction of prostate cancer Gleason score using enlarged region of interest

BACKGROUND

Prostate cancer (PCa) is one of the most common cancers in men worldwide, and its timely diagnosis and treatment are becoming increasingly important. MRI is in increasing use to diagnose cancer and to distinguish between non-clinically significant and clinically significant PCa, leading to more precise diagnosis and treatment. The purpose of this study is to present a radiomics-based method for determining the Gleason score (GS) for PCa using tumour heterogeneity on multiparametric MRI (mp-MRI).

METHODS

Twenty-six patients with biopsy-proven PCa were included in this study. The quantitative T2 values, apparent diffusion coefficient (ADC) and signal enhancement rates (α) were calculated using multi-echo T2 images, diffusion-weighted imaging (DWI) and dynamic contrast-enhanced MRI (DCE-MRI), for the annotated region of interests (ROI). After texture feature analysis, ROI range expansion and feature filtering was performed. Then obtained data were put into support vector machine (SVM), K-Nearest Neighbor (KNN) and other classifiers for binary classification.

RESULTS

The highest classification accuracy was 73.96% for distinguishing between clinically significant (Gleason 3 + 4 and above) and non-significant cancers (Gleason 3 + 3) and 83.72% for distinguishing between Gleason 3 + 4 from Gleason 4 + 3 and above, which was achieved using initial ROIs drawn by the radiologists. The accuracy improved when using expanded ROIs to 80.67% using SVM and 88.42% using Bayesian classification for distinguishing between clinically significant and non-significant cancers and Gleason 3 + 4 from Gleason 4 + 3 and above, respectively.

CONCLUSIONS

Our results indicate the research significance and value of this study for determining the GS for prostate cancer using the expansion of the ROI region.

Effectiveness and Accuracy of MRI-Ultrasound Fusion Targeted Biopsy Based on PI-RADS v2.1 Category in Transition/Peripheral Zone of the Prostate

BACKGROUND

MRI-ultrasound fusion targeted biopsy (MRI-TBx) improves the clinically significant prostate cancer (csPCa) detection with fewer cores. However, whether systematic biopsy-guided by transrectal ultrasound (TRUS-SBx) can be omitted when undergoing MRI-TBx in transition zone (TZ) and peripheral zone (PZ) remains unclear.

PURPOSE

To assess the performance and effectiveness of MRI-TBx based on PI-RADS v2.1 for csPCa diagnosis in TZ and PZ, respectively.

STUDY TYPE

Retrospective.

SUBJECTS

A total of 309 selected cases (median age 70 years) with 356 lesions who underwent both MRI-TBx and TRUS-SBx were enrolled.

FIELD STRENGTH/SEQUENCE

A 3.0 T, multiparametric MRI (mp-MRI) including T2-weighted turbo-spin echo imaging (T2WI), diffusion-weighted spin-echo echo planar imaging (DWI), dynamic contrast-enhanced MRI with time-resolved T1-weighted imaging (DCE).

ASSESSMENT

Mp-MRI was assessed by two radiologists using PI-RADS v2.1. The csPCa detection rates provided by MRI-TBx, TRUS-SBx and combined biopsy in TZ and PZ were calculated, respectively.

STATISTICAL TESTS

McNemar test was used to compare the csPCa detection rates in TZ and PZ, respectively. The frequencies and distribution of all detected prostate cancers by different biopsy methods were also compared. P < 0.05 was considered statistically significant.

RESULTS

Among 356 lesions in 309 patients, 208 (68 in TZ, 140 in PZ) were pathologically confirmed as csPCa. In TZ, there were significant differences for csPCa detection with PI-RADS 3 between combined biopsy and TRUS-SBx (23.5% vs. 15.3%), MRI-TBx (23.5% vs. 16.3%), respectively. MRI-TBx detected 23% (19/83) cases missed by TRUS-SBx in which 68% (13/19) were csPCa. In PZ, there were no statistical differences between MRI-TBx and combined biopsy with PI-RADS 3-5 (P = 0.21, 0.25, 0.07, respectively). In 9% (14/152) cases only detected by MRI-TBx, 86% (12/14) were clinically significant. Five percent (7/152) of cases only detected by TRUS-SBx were completely nonclinically significant.

DATA CONCLUSION

MRI-TBx played a positive role on csPCa diagnosis in TZ, but combined biopsy might be the best choice especially in the subgroup PI-RADS 3. In PZ, MRI-TBx had an advantage over TRUS-SBx for csPCa detection.

EVIDENCE LEVEL

2.

TECHNICAL EFFICACY

Stage 2.

Impact of Magnetic Resonance Imaging Targeting on Pathologic Upgrading and Downgrading at Prostatectomy: A Systematic Review and Meta-analysis

CONTEXT

The evidence supporting multiparametric magnetic resonance imaging (MRI) targeting for biopsy is nearly exclusively based on biopsy pathologic outcomes. This is problematic, as targeting likely allows preferential identification of small high-grade areas of questionable oncologic significance, raising the likelihood of overdiagnosis and overtreatment.

OBJECTIVE

To estimate the impact of MRI-targeted, systematic, and combined biopsies on radical prostatectomy (RP) grade group concordance.

EVIDENCE ACQUISITION

PubMed MEDLINE and Cochrane Library were searched from July 2018 to January 2022. Studies that conducted systematic and MRI-targeted prostate biopsies and compared biopsy results with pathology after RP were included. We performed a meta-analysis to assess whether pathologic upgrading and downgrading were influenced by biopsy type and a net-benefit analysis using pooled risk difference estimates.

EVIDENCE SYNTHESIS

Both targeted only and combined biopsies were less likely to result in upgrading (odds ratio [OR] vs systematic of 0.70, 95% confidence interval [CI] 0.63-0.77, p < 0.001, and 0.50, 95% CI 0.45-0.55, p < 0.001), respectively). Targeted only and combined biopsies increased the odds of downgrading (1.24 (95% CI 1.05-1.46), p = 0.012, and 1.96 (95% CI 1.68-2.27, p < 0.001) compared with systematic biopsies, respectively. The net benefit of targeted and combined biopsies is 8 and 7 per 100 if harms of up- and downgrading are considered equal, but 7 and -1 per 100 if the harm of downgrading is considered twice that of upgrading.

CONCLUSIONS

The addition of MRI-targeting results in lower rates of upgrading as compared to systematic biopsy at RP (27% vs 42%). However, combined MRI-targeted and systematic biopsies are associated with more downgrading at RP (19% v 11% for combined vs systematic). Strong heterogeneity suggests further research into factors that influence the rates of up- and downgrading and that distinguishes clinically relevant from irrelevant grade changes is needed. Until then, the benefits and harms of combined MRI-targeted and systematic biopsies cannot be fully assessed.

PATIENT SUMMARY

We reviewed the ability of magnetic resonance imaging (MRI)-targeted biopsies to predict cancer grade at prostatectomy. We found that combined MRI-targeted and systematic biopsies result in more cancers being downgraded than systematic biopsies.

Direct comparison between Grade Group assessed on systematic and MRI/ultrasound fusion targeted biopsies correlated to the radical prostatectomy specimens in patients with prostate cancer

OBJECTIVES

To compare the correlation of Gleason score (GS) and ISUP grade determined by prostate biopsies (PBx) and radical prostatectomy (RP) specimens according to the biopsy technique: ultrasound randomised (RBx) vs. MRI/ultrasound fusion targeted (TBx).

MATERIALS AND METHODS

Between March 2013 and June 2018, we retrospectively included patients who underwent RP for prostate cancer (PCa) histopathologically proven by RBx and/or TBx. All patients had a prebiopsy MRI by a single radiologist (using PI-RADS score), then transrectal RBx (12cores, blinded to MRI lesions) and TBx (2-4 cores/target) with elastic MRI/ultrasound fusion (UroStation™, Koelis, Grenoble, France). Histological findings were compared: PBx vs. RP.

RESULTS

One hundred and four patients underwent RP after RBx and/or TBx. ISUP concordance rate was better with the association RBx+TBx 49% (51/104) vs. 43.3% with TBx (P=0.07) and 43.3% with RBx (P=0.13). With RBx, 50% of the patients were downgraded (52/104) against 42.3% (44/104) with TBx (P=0.088). The association RBx+TBx significantly decreased the rate of downgrading of the ISUP score compared to the ISUP score of RP 35.6% (37/104) vs. RBx (50%, P=0.0001) and vs. TBx (42.3%, P=0.016).

CONCLUSION

In half of cases, the ISUP score was underestimated in RBx compared to RP specimens. Adding TBx to RBx significantly reduced downgrading. The combination of both biopsy techniques appeared to be the best protocol to get closer to ISUP score and GS of the RP specimens.

LEVEL OF EVIDENCE

C.

Inter-Reader Variability Using PI-RADS v2 Versus PI-RADS v2.1: Most New Disagreement Stems from Scores 1 and 2

PURPOSE

To analyze possible differences in the inter-reader variability between PI-RADS version 2 (v2) and version 2.1 (v2.1) for the classification of prostate lesions using multiparametric MRI (mpMRI) of the prostate.

METHODS

In this retrospective and randomized study, 239 annotated and histopathologically correlated prostate lesions (104 positive and 135 negative for prostate cancer) were rated twice by three experienced uroradiologists using PI-RADS v2 and v2.1 with an interval of at least two months between readings. Results were tabulated across readers and reading timepoints and inter-reader variability was determined using Fleiss' kappa (κ). Thereafter, an additional analysis of the data was performed in which PI-RADS scores 1 and 2 were combined, as they have the same clinical consequences.

RESULTS

PI-PI-RADS v2.1 showed better inter-reader agreement in the peripheral zone (PZ), but poorer inter-reader agreement in the transition zone (TZ) (PZ: κ = 0.63 vs. κ = 0.58; TZ: κ = 0.47 vs. κ = 0.57). When PI-RADS scores 1 and 2 were combined, the use of PI-RADS v2.1 resulted in almost perfect inter-reader agreement in the PZ and substantial agreement in the TZ (PZ: κ = 0.81; TZ: κ = 0.80).

CONCLUSION

PI-RADS v2.1 improves inter-reader agreement in the PZ. New differences in inter-reader agreement were mainly the result of the assignment of PI-RADS v2.1 scores 1 and 2 to lesions in the TZ. Combining scores 1 and 2 improved inter-reader agreement both in the TZ and in the PZ, indicating that refined definitions may be warranted for these PI-RADS scores.

KEY POINTS

· PI-RADSv2.1 improves inter-reader agreement in the PZ but not in the TZ.. · New differences derived from PI-RADSv2.1 scores 1 and 2 in the TZ.. · Combined PI-RADSv2.1 scores of 1 and 2 yielded better inter-reader agreement.. · PI-RADSv2.1 appears to provide more precise description of lesions in the PZ.. · Improved inter-reader agreement in the PZ stresses the importance of appropriate lexicon description..

CITATION FORMAT

· Beetz N, Haas M, Baur A et al. Inter-Reader Variability Using PI-RADS v2 Versus PI-RADS v2.1: Most New Disagreement Stems from Scores 1 and 2. Fortschr Röntgenstr 2022; 194: 852 - 861.

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.

Machine Learning-Based Prediction of Pathological Upgrade From Combined Transperineal Systematic and MRI-Targeted Prostate Biopsy to Final Pathology: A Multicenter Retrospective Study

Objective

This study aimed to evaluate the pathological concordance from combined systematic and MRI-targeted prostate biopsy to final pathology and to verify the effectiveness of a machine learning-based model with targeted biopsy (TB) features in predicting pathological upgrade.

Materials and Methods

All patients in this study underwent prostate multiparametric MRI (mpMRI), transperineal systematic plus transperineal targeted prostate biopsy under local anesthesia, and robot-assisted laparoscopic radical prostatectomy (RARP) for prostate cancer (PCa) sequentially from October 2016 to February 2020 in two referral centers. For cores with cancer, grade group (GG) and Gleason score were determined by using the 2014 International Society of Urological Pathology (ISUP) guidelines. Four supervised machine learning methods were employed, including two base classifiers and two ensemble learning-based classifiers. In all classifiers, the training set was 395 of 565 (70%) patients, and the test set was the remaining 170 patients. The prediction performance of each model was evaluated by area under the receiver operating characteristic curve (AUC). The Gini index was used to evaluate the importance of all features and to figure out the most contributed features. A nomogram was established to visually predict the risk of upgrading. Predicted probability was a prevalence rate calculated by a proposed nomogram.

Results

A total of 515 patients were included in our cohort. The combined biopsy had a better concordance of postoperative histopathology than a systematic biopsy (SB) only (48.15% vs. 40.19%, p = 0.012). The combined biopsy could significantly reduce the upgrading rate of postoperative pathology, in comparison to SB only (23.30% vs. 39.61%, p < 0.0001) or TB only (23.30% vs. 40.19%, p < 0.0001). The most common pathological upgrade occurred in ISUP GG1 and GG2, accounting for 53.28% and 20.42%, respectively. All machine learning methods had satisfactory predictive efficacy. The overall accuracy was 0.703, 0.768, 0.794, and 0.761 for logistic regression, random forest, eXtreme Gradient Boosting, and support vector machine, respectively. TB-related features were among the most contributed features of a prediction model for upgrade prediction.

Conclusion

The combined effect of SB plus TB led to a better pathological concordance rate and less upgrading from biopsy to RP. Machine learning models with features of TB to predict PCa GG upgrading have a satisfactory predictive efficacy.

Integration of Prostate Biopsy Results with Pre-Biopsy Multiparametric Magnetic Resonance Imaging Findings Improves Local Staging of Prostate Cancer

PURPOSE

To assess the added value of histological information for local staging of prostate cancer (PCa) by comparing the accuracy of multiparametric MRI alone (mpMRI) and mpMRI with biopsy Gleason grade (mpMRI+Bx).

METHODS

133 consecutive patients who underwent preoperative 3T-MRI and subsequent radical prostatectomy for PCa were included in this single-centre retrospective study. mpMRI imaging was reviewed independently by two uroradiologists for the presence of extracapsular extension (ECE) and seminal vesicle invasion (SVI) on a 5-point Likert scale. For second reads, the radiologists received results of targeted fused MR/US biopsy (mpMRI+Bx) prior to re-staging.

RESULTS

The median patient age was 63 years (interquartile range (IQR) 58-67 years) and median PSA was 6.5 ng/mL (IQR 5.0-10.0 ng/mL). Extracapsular extension was present in 85/133 (63.9%) patients and SVI was present in 22/133 (16.5%) patients. For ECE prediction, mpMRI showed sensitivity and specificity of 63.5% and 81.3%, respectively, compared to 77.7% and 81.3% achieved by mpMRI+Bx. At an optimal cut-off value of Likert score ≥ 3, areas under the curves (AUCs) was .85 for mpMRI+Bx and .78 for mpMRI, P < .01. For SVI prediction, AUC was .95 for mpMRI+Bx compared to .92 for mpMRI; P = .20. Inter-reader agreement for ECE and SVI prediction was substantial for mpMRI (k range, .78-.79) and mpMRI+Bx (k range, .74-.79).

CONCLUSIONS

MpMRI+Bx showed superior diagnostic performance with an increased sensitivity for ECE prediction but no significant difference for SVI prediction. Inter-reader agreement was substantial for both protocols. Integration of biopsy information adds value when staging prostate mpMRI.

Combination MRI-targeted and systematic prostate biopsy may overestimate gleason grade on final surgical pathology and impact risk stratification

PURPOSE

Gleason grade (GG) on prostate biopsy is important for risk stratification and clinical decision making. Multiparametric MRI (mpMRI) improved detection of clinically significant disease and some studies suggest that MRI-fusion biopsy combined with systematic biopsy results in fewer upgrades on final surgical pathology. However, the downgrade rate is unclear and there is controversy in the literature. The objectives of this study are to assess the concordance of combination biopsy with final surgical pathology, and furthermore, to specifically determine downgrade rates.

MATERIALS AND METHODS

In our institutional mpMRI-ultrasound fusion biopsy database, 173 underwent targeted and systematic biopsy followed by radical prostatectomy (RP). GG on targeted, systematic and combination (targeted and systematic) biopsy were compared with GG on RP. Concordance rates between biopsy types were compared with the McNemar test. Proportion of GG upgrade or downgrade at the time of RP was also evaluated.

RESULTS

Surgical pathology was concordant with 44.5% of systematic biopsies, 46.8% of targeted biopsies, and 56.7% of combination biopsies. Combination biopsy significantly overestimated the final GG on RP compared to systematic biopsy (16.8% vs. 8.7% RR 1.93, 95% CI 1.36-2.75, P < 0.001). Downgrade rate from unfavorable to favorable intermediate-risk disease was 46.2%, and from high-risk to intermediate-risk disease was 45.1%.

CONCLUSIONS

Combination (targeted and systematic) biopsy is associated with the highest concordance rate between biopsy and RP pathology when compared with systematic or targeted biopsy alone. However, targeting MRI lesions and therefore the higher risk components, may at times overestimate the final surgical pathology which can result in overtreatment of what may truly be less aggressive disease.

Optimal Method for Reporting Prostate Cancer Grade in MRI-targeted Biopsies

When multiple cores are biopsied from a single magnetic resonance imaging (MRI)-targeted lesion, Gleason grade may be assigned for each core separately or for all cores of the lesion in aggregate. Because of the potential for disparate grades, an optimal method for pathology reporting MRI lesion grade awaits validation. We examined our institutional experience on the concordance of biopsy grade with subsequent radical prostatectomy (RP) grade of targeted lesions when grade is determined on individual versus aggregate core basis. For 317 patients (with 367 lesions) who underwent MRI-targeted biopsy followed by RP, targeted lesion grade was assigned as (1) global Grade Group (GG), aggregated positive cores; (2) highest GG (highest grade in single biopsy core); and (3) largest volume GG (grade in the core with longest cancer linear length). The 3 biopsy grades were compared (equivalence, upgrade, or downgrade) with the final grade of the lesion in the RP, using κ and weighted κ coefficients. The biopsy global, highest, and largest GGs were the same as the final RP GG in 73%, 68%, 62% cases, respectively (weighted κ: 0.77, 0.79, and 0.71). For cases where the targeted lesion biopsy grade scores differed from each other when assigned by global, highest, and largest GG, the concordance with the targeted lesion RP GG was 69%, 52%, 31% for biopsy global, highest, and largest GGs tumors (weighted κ: 0.65, 0.68, 0.59). Overall, global, highest, and largest GG of the targeted biopsy show substantial agreement with RP-targeted lesion GG, however targeted global GG yields slightly better agreement than either targeted highest or largest GG. This becomes more apparent in nearly one third of cases when each of the 3 targeted lesion level biopsy scores differ. These results support the use of global (aggregate) GG for reporting of MRI lesion-targeted biopsies, while further validations are awaited.

Combined Systematic and MRI-US Fusion Prostate Biopsy Has the Highest Grading Accuracy When Compared to Final Pathology

Background and objectives: Systematic prostate biopsy (SB) has a low Gleason group (GG) accuracy when compared to final pathology. This may negatively impact the inclusion of patients into specific risk groups and treatment choice. The aim of our study was to assess the GG accuracy of magnetic resonance imaging-ultrasound (MRI-US) fusion prostate biopsy. Materials and Methods: Of a cohort of minimally invasive radical prostatectomy (RP), we selected all patients who were diagnosed with prostate cancer (PCa) via MRI-US fusion biopsy (n = 115). Results: Combined biopsy had the highest rate for GG concordance (61.7% vs. 60.4% for SB vs. 45.3% for MRI-US fusion biopsy) and the lowest for upgrading (20.9% vs. 24.5% for SB vs. 34.9% for MRI-US fusion biopsy), p < 0.0001. No clinical data were predictive for upgrading or downgrading at final pathology. Locally advanced PCa was associated with a high Prostate Imaging-Reporting and Data System (PIRADS) score (p = 0.0014) and higher percentages of positive biopsy cores (PBC)/targeted (p = 0.0002) and PBC/total (p = 0.01). Positive surgical margins were correlated with higher percentages of PBC/systematic (p = 0.003) and PBC/total (p = 0.009). Conclusions: Pre-biopsy prostate MRI improves GG concordance between biopsy and RP. Combined biopsy provides the highest grading accuracy when compared to final pathology. Targeted and systematic biopsy data are predictive for adverse pathologic outcomes.

Correlation of MRI-Lesion Targeted Biopsy vs. Systematic Biopsy Gleason Score with Final Pathological Gleason Score after Radical Prostatectomy

Background: The impact of MRI-lesion targeted (TB) and systematic biopsy (SB) Gleason score (GS) as a predictor for final pathological GS still remains unclear. Methods: All patients with TB + SB, and subsequent radical prostatectomy (RP) between 01/2014-12/2020 were analyzed. Rank correlation coefficient predicted concordance with pathological GS for patients’ TB and SB GS, as well as for the combined effect of SB + TB. Results: Of 159 eligible patients, 77% were biopsy naïve. For SB taken in addition to TB, a Spearman’s correlation of +0.33 was observed regarding final GS. Rates of concordance, upgrading, and downgrading were 37.1, 37.1 and 25.8%, respectively. For TB, a +0.52 correlation was computed regarding final GS. Rates of concordance, upgrading and downgrading for TB biopsy GS were 45.9, 33.3, and 20.8%, respectively. For the combination of SB + TB, a correlation of +0.59 was observed. Rates of concordance, upgrading and downgrading were 49.7, 15.1 and 35.2%, respectively. The combined effect of SB + TB resulted in a lower upgrading rate, relative to TB and SB (both p < 0.001), but a higher downgrading rate, relative to TB (p < 0.01). Conclusions: GS obtained from TB provided higher concordance and lower upgrading and downgrading rates, relative to SB GS with regard to final pathology. The combined effect of SB + TB led to the highest concordance rate and the lowest upgrading rate.

Multi-Bevel Needle Design Enabling Accurate Insertion in Biopsy for Cancer Diagnosis

OBJECTIVE

To obtain definitive cancer diagnosis for suspicious lesions, accurate needle deployment and adequate tissue sampling in needle biopsy are essential. However, the single-bevel needles in current biopsy devices often induce deflection during insertion, potentially causing lesion missampling/undersampling and cancer misdiagnosis. This study aims to reveal the biopsy needle design criteria enabling both low deflection and adequate tissue sampling.

METHODS

A novel model capable of predicting needle deflection and tissue deformation was first established to understand needle-tissue interaction with different needle tip geometries. Experiments of needle deflection and ex-vivo tissue biopsy were conducted for model validation.

RESULTS

The developed model showed a reasonably good prediction on the correlation of needle tip type vs. the resultant needle deflection and tissue sampling length. A new multi-bevel needle with the tissue separation point below the needle groove face has demonstrated to be an effective design with an 87% reduction in deflection magnitude and equivalently long tissue sampling length compared to the current single-bevel needle.

CONCLUSION

This study has revealed two critical design criteria for biopsy needles: 1) multiple bevel faces at the needle tip can generate forces to balance bending moments during insertion to enable a low needle deflection and 2) the tissue separation point should be below the needle groove face to ensure long tissue sampling length.

SIGNIFICANCE

The developed methodologies and findings in this study serve as proof-of-concept and can be utilized to investigate various biopsy procedures to improve cancer diagnostic accuracy as well as other procedures requiring accurate needle insertion.

Comparison of TRUS and combined MRI-targeted plus systematic prostate biopsy for the concordance between biopsy and radical prostatectomy pathology

AIM

To evaluate the accuracy in histologic grading of MRI/US image fusion biopsy by comparing conventional 12-core TRUS-Bx at radical prostatectomy specimens (RP).

METHODS

Consecutive patients diagnosed prostate cancer (127 with combination of both targeted biopsy (TBx) plus systematic biopsies (SBx) and separate patient cohort of 330 conventional TRUS-Bx without mpMRI) with a PSA level of <20 ng/mL prior to RP were included. The primary end point was the grade group concordance between biopsy and RP pathology according to biopsy technique.

RESULTS

Clinically significant prostate cancer detection was 51.2% for TRUS-Bx, 49.5% for SBx, 67% for TBx and 75.7% for TBx + SBx. Upgrading and downgrading of at least one Gleason Grade Group (GGG) was recorded in 43.3%/ 6.7% patients of the TRUS-Bx and in 20.5%/ 22% of the TBX + SBx group, respectively (all P < .001). Concordance level was detected to be significantly higher for ISUP 1 in combined TBx + SBx method compared to conventional TRUS-Bx (61.3% vs 37.9%, P = .014). In ISUP 1 exclusively, significant upgrading was seen in TRUS-Bx (62.1%) when compared to TBx (41.4%) and TBx + SBx (38.7%).

CONCLUSIONS

MRI-targeted biopsies detected more significant PCa than TRUS-Bx but, superiority in significant cancer detection appears as a result of inadvertant selective sampling of small higher grade areas. Within an otherwise low grade cancer and does not reflect accurate GGG final surgical pathology. TBx + SBx has the greatest concordance in ISUP Grade 1 with less upgrading which is utmost important for active surveillance.

Vascular-targeted Photodynamic Therapy in Unilateral Low-risk Prostate Cancer in Germany: 2-yr Single-centre Experience in a Real-world Setting Compared with Radical Prostatectomy

BACKGROUND

Vascular-targeted photodynamic therapy (VTP) is an approved treatment option for unilateral low-risk prostate cancer (PCa).

OBJECTIVE

Herein, we report our initial experience of patients treated by VTP. We compared short-term functional and oncological outcomes with those of a consecutive cohort of patients undergoing radical prostatectomy (RP) for unilateral low-risk PCa.

DESIGN, SETTING, AND PARTICIPANTS

Patients with unilateral low-risk PCa undergoing VTP (n = 41) and RP (n = 49) were evaluated in a real-world setting.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Oncological outcome after VTP was measured by magnetic resonance imaging-based rebiopsy at 12 and 24 mo. Functional outcome after 1 yr was investigated by International Index of Erectile Function 5 and International Prostate Symptom Score questionnaires. Continence was evaluated by pad use.

RESULTS AND LIMITATIONS

In 12- and 24-mo control biopsy (n = 22) after VTP, 45% of VTP patients showed no evidence of PCa. Both low- and intermediate-risk PCa were detected in 27% of patients. None of the RP patients had a PCa recurrence. Of VTP and RP patients, 71% and 30%, respectively, preserved erectile function. Of VTP patients, 88% had no bladder outlet obstruction. Of RP patients, 96% and 4% used zero to one and two or more pads per day, respectively. Data acquisition was performed outside of a clinical trial. The short-term follow-up and the small number of rebiopsied patients have to be considered.

CONCLUSIONS

VTP is a promising treatment option in unilateral low-risk PCa presenting a lower complication profile than RP in a real-world setting. However, recurrence and progression after VTP are common in this low-risk PCa cohort, and have to be discussed critically with patients who wish VTP instead of active surveillance. Therefore, a rigorous surveillance strategy with multiparametric magnetic resonance imaging and control biopsy is required.

PATIENT SUMMARY

Vascular-targeted photodynamic therapy (VTP) is a promising therapy option in patients with unilateral low-risk prostate cancer. However, tumour recurrence has to be taken into account. Noninferiority of VTP to standard curative treatment options still has to be confirmed.

Postoperative change in Gleason score of prostate cancer in fusion targeted biopsy: a matched pair analysis

OBJECTIVE

To evaluate if MRI/ultrasound fusion based targeted biopsy (FBx) leads to a reduced rate of change in Gleason score (GS) compared to prostatectomy specimen.

METHODS

The histopathological findings of the biopsy of the prostate and the radical prostatectomy (RP) specimen of 210 patients who were referred to our hospital between 2012 and 2017 were compared retrospectively in this study. One hundred and five patients who underwent FBx combined with ultrasound-guided 12-core biopsy of the prostate (SBx) were matched with 105 patients who underwent SBx only. This study evaluated the rate of up- or downgrading in the RP specimen in both groups and compared the results via matched pair analysis.

RESULTS

Concordance in Gleason grade group (GGG) was found in 52/105 patients (49.5%) in SBx and in 49/105 patients (46.7%) with FBx (p = 0.679). The rate of downgrading was statistically significant (p = 0.014) and was higher in the FBx group (14/105 patients, 13.3%) than in the SBx group (4/105 patients, 3.8%). A higher rate of upgrading was seen in SBx (49/105 patients; 46.7%) compared to FBx (42/105 patients; 40%), with no statistical significance (p = 0.331). The change in GGG from biopsy to final pathology in patients with GGG 1 and 2 at biopsy level was not statistically significant (p = 0.168).

CONCLUSION

FBx does not decrease the rate of upgrading between biopsy and final pathology in RP specimens. Our results indicate that FBx tends to overestimate the final GGG compared to SBx.

Histopathological Ratios to Predict Gleason Score Agreement between Biopsy and Radical Prostatectomy

Biopsy proven Gleason score is essential to decide treatment modalities for prostate cancer, either surgical (radical prostatectomy) or non-surgical (active surveillance, watchful waiting, radiation therapy and hormone therapy). Several studies indicated that biopsy proven Gleason score may underestimate Gleason score at radical prostatectomy, hence we aimed to calculate the minimum length of biopsy cores needed to have Gleason score agreement. We evaluated 115 prostate cancer patients who underwent multiparametric magnetic resonance/transperineal ultrasonography fusion biopsy and subsequently, radical prostatectomy. Biopsy proven Gleason score was consistent with Gleason score at subsequent radical prostatectomy in 82.6% of patients, while in 17.4% of patients, Gleason score was higher at radical prostatectomy. Gleason score agreement showed a strong direct association with a ratio > 0.05 between the total volume of biopsies performed in tumor area and the volume of the corresponding tumor at radical prostatectomy. A significant association was also found with a ratio ≥ 0.0034 between the tumor volume in the biopsy and the volume of the corresponding tumor at radical prostatectomy and with a ratio ≥ 0.086 between the tumor volume in the biopsy and the total volume of biopsies performed in the tumor area. These results could be exploited to calculate the minimum length of biopsy cores needed to have a correct Gleason score estimation and therefore be used in fusion targeted biopsies with volume adjustments.

Mosquito proboscis-inspired needle insertion to reduce tissue deformation and organ displacement

This study investigates mosquito proboscis-inspired (MPI) insertion applied to the clinically used biopsy needle to reduce tissue deformation and organ displacement. Advanced medical imagining has enabled early-stage identification of cancerous lesions that require needle biopsy for minimally invasive tissue sampling and pathological analysis. Accurate cancer diagnosis depends on the accuracy of needle deployment to the targeted cancerous lesion site. However, currently available needle delivery systems deform and move soft tissue and organs, leading to a non-diagnostic biopsy or undersampling of the target. Two features inspired by the mosquito proboscis were adopted for MPI insertion in prostate biopsy: (1) the harpoon-shape notches at the needle tip and (2) reciprocating needle-cannula motions for incremental insertion. The local tissue deformation and global prostate displacement during the MPI vs. traditional direct insertions were quantified by optically tracking the displacement of particle-embedded tissue-mimicking phantoms. Results show that the MPI needle insertion reduced both local tissue deformation and global prostate displacement because of the opposite needle-cannula motions and notches which stabilized and reduced the tissue deformation during insertion. Findings provide proof of concept for MPI insertion in the clinical biopsy procedures as well as insights of needle–tissue interaction for future biopsy technology development.

Pathological findings at radical prostatectomy of biopsy naïve men diagnosed with MRI targeted biopsy alone without concomitant standard systematic sampling

OBJECTIVES

To test international society of urological pathology grade group (ISUP GG) concordance rates between multiparametric magnetic resonance imaging (mpMRI) targeted biopsies (TB) vs. standard systematic biopsies (SB) and radical prostatectomy (RP) specimens, in biopsy naïve patients.

MATERIALS AND METHODS

This retrospective single center study included 80 vs. 500 biopsy naïve patients diagnosed with TB vs. SB and treated with RP between 2015 and 2018. First, we compared ISUP GG concordance rates and the percentages of undetected clinically significant prostate cancer (csPCa: ISUP GG  ≥ 3), between TB vs. SB and RP. Second, multivariable logistic regression models tested predictors of concordance rates before and after 1:3 propensity score (PS) matching. Third, among TB patients, univariable logistic regression models tested variables associated with ISUP GG concordance at RP.

RESULTS

Overall, ISUP GG concordance rates were, respectively, 55 vs. 41.4% for TB vs. SB (P = 0.02). However, no differences in concordance rates were observed in patients with biopsy ISUP GG1 (31 vs. 33.9% for TB vs. SB; P = 0.8). Moreover, 15 vs. 18.8% csPCa were missed by TB vs. SB, respectively (P = 0.4). In multivariable logistic regression models, TB were associated with higher concordance rates before (odds ratio [OR]: 1.13; P = 0.04) and after 1:3 PS matching (OR: 1.15; P 0.03), compared to SB. In TB patients, age (OR: 0.98; P = 0.04), maximum cancer core involvement (MCCI; OR: 1.02; P = 0.02) and maximum cancer core length (MCCL; OR: 1.01; P = 0.07) were associated with ISUP GG concordance. Moreover, a trend for lower concordance rates was observed with higher PSA-D (OR: 0.77; P = 0.1). Finally, intermediate lesion location at mpMRI was associated with lowest concordance rates (44%).

CONCLUSION

In biopsy naïve patients treated with RP, TB achieved higher rates of ISUP GG concordance, but same percentages of csPCa missed, compared to SB. Moreover, only patients with ISUP GG ≥2, but not patients with ISUP GG1, exhibited higher concordance rates. Finally, age, MCCI, MCCL, PSA-D, and lesion location were associated with concordance between TB and RP.

Power Doppler Sonography (PDS) and Modified TRUS Systematic Biopsies - Can this Combination Adequately Replace Multiparametric Prostate Magnetic Resonance Imaging (mp-MRI) in Candidates for Re Biopsies Who cannot Undergo mp-MRI

The MRI targeted biopsy (MRI-TBx) may increase the detection rate of clinically significant cancer (csPCa) in candidates for re-biopsy. However, there will be several patients in whom MRI is contraindicated. In this retrospective study we assessed the ability of combination of PDS guided biopsies (PDS-TBx) and modified SBx to substitute MRI-TBx. 154 men with persistently elevated PSA were referred for re-biopsy. Our protocol included a combination of MRI-TBx, DPS-TBx and modified SBx with additional biopsies from anterior lateral horns and anterior aspects of apex. MRI findings were defined as suspicious lesions (MRI-SL) and highly suspicious lesions (MRI-HL), based on PIRADS scale. In 40 patients csPCa was detected. While, MRI diagnosed csPCa in 36 patients (23%, n-36/154): 25% and 92% of biopsies targeted to the MRI- SL and MRI-HSL confirmed csPCa. Thirty-eight PDS hypervascular areas were found, while csPCa was diagnosed in 84% of these lesions, or in 28 patients (18%, n-28/154). SBx detected csPCa in 34 cores or in 21 patients (13%, n - 21/154). SBx missed cancers in the in the anterior aspect of middle gland. Combination of PDS-TBx + SBx detected csPCa in 35 (88% of csPCa) patients. Strongest predictors for the csPCa presence were MRI-HSL, PDS' lesions and biopsies from anterior aspect that included apex, mid gland and anterior lateral horns (p < 0.001 and p-0.008, respectively). The combination of PDS-TBx + SBx may miss 15% of csPCa detected by MRI. However, it can detect additional 10% of csPCa that were missed by MRI. To improve the accuracy of this combination, the anterior aspect of middle gland should be also included in the modified SBx. These changes in combination can make it helpful in candidates for re-biopsy who cannot undergo MRI.

Prediction of prostate cancer Gleason score upgrading from biopsy to radical prostatectomy using pre-biopsy multiparametric MRI PIRADS scoring system

An increase or ‘upgrade’ in Gleason Score (GS) in prostate cancer following Transrectal Ultrasound (TRUS) guided biopsies remains a significant challenge to overcome. to evaluate whether MRI has the potential to narrow the discrepancy of histopathological grades between biopsy and radical prostatectomy, three hundred and thirty men treated consecutively by laparoscopic radical prostatectomy (LRP) between July 2014 and January 2019 with localized prostate cancer were included in this study. Independent radiologists and pathologists assessed the MRI and histopathology of the biopsies and prostatectomy specimens respectively. A multivariate model was constructed using logistic regression analysis to assess the ability of MRI to predict upgrading in biopsy GS in a nomogram. A decision-analysis curve was constructed assessing impact of nomogram using different thresholds for probabilities of upgrading. PIRADS scores were obtained from MRI scans in all the included cases. In a multivariate analysis, the PIRADS v2.0 score significantly improved prediction ability of MRI scans for upgrading of biopsy GS (p = 0.001, 95% CI [0.06–0.034]), which improved the C-index of predictive nomogram significantly (0.90 vs. 0.64, p < 0.05). PIRADS v2.0 score was an independent predictor of postoperative GS upgrading and this should be taken into consideration while offering treatment options to men with localized prostate cancer.

Improvement of the intermediate risk prostate cancer sub-classification by integrating MRI and fusion biopsy features

INTRODUCTION

Treatment decision-making for intermediate-risk prostate cancer (CaP) is mainly based on grade and tumor involvement on systematic biopsy. We aimed to assess the added value of multi-parametric magnetic resonance imaging (mpMRI) and targeted biopsy (TB) features for predicting final pathology and for improving the well-established favourable/unfavourable systematic biopsy-based sub-classification.

MATERIALS AND METHODS

From a prospective database of 377 intermediate risk CaP cases, we evaluated the performance of the standard intermediate risk classification (IRC), and the predictive factors for unfavourable disease on final pathology aiming to build a new model. Overall unfavourable disease (OUD) was defined by any pT3-4 and/or pN1 and/or grade group (GG) ≥ 3.

RESULTS

The standard IRC was found to be predictive for unfavourable disease in this population. However, in multivariable analysis regression, ECE on mpMRI and GG ≥3 on TB remained the 2 independent predictive factors for OUD disease (HR = 2.7, P = 0.032, and HR = 2.41, P = 0.01, respectively). By using the new IRC in which unfavorable risk was defined by ECE on mpMRI and/or GG ≥3 on TB, the proportion of unfavorable cases decreased from 62.3% to 34.1% while better predicting unfavorable disease in RP speciments. The new model displayed a better accuracy than the standard IRC for predicting OUD (AUC: 0.66 vs. 0.55).

CONCLUSIONS

The integration of imaging and TB features drastically improves the intermediate risk sub-classification performance and better discriminates the unfavourable risk group that could benefit from more aggressive therapy such as neo-adjuvant and/or adjuvant treatment, and the favourable group that could avoid over-treatment. External validation in other datasets is needed.

Needle deflection and tissue sampling length in needle biopsy

This study investigates the effect of needle tip geometry on the needle deflection and tissue sampling length in biopsy. Advances in medical imaging have allowed the identification of suspicious cancerous lesions which then require needle biopsy for tissue sampling and subsequent confirmatory pathological analysis. Precise needle insertion and adequate tissue sampling are essential for accurate cancer diagnosis and individualized treatment decisions. However, the single-bevel needles in current hand-held biopsy devices often deflect significantly during needle insertion, causing variance in the targeted and actual locations of the sampled tissue. This variance can lead to inaccurate sampling and false-negative results. There is also a limited understanding of factors affecting the tissue sampling length which is a critical component of accurate cancer diagnosis. This study compares the needle deflection and tissue sampling length between the existing single-bevel and exploratory multi-bevel needle tip geometries. A coupled Eulerian-Lagrangian finite element analysis was applied to understand the needle-tissue interaction during needle insertion. The needle deflection and tissue sampling length were experimentally studied using tissue-mimicking phantoms and ex-vivo tissue, respectively. This study reveals that the tissue separation location at the needle tip affects both needle deflection and tissue sampling length. By varying the tissue separation location and creating a multi-bevel needle tip geometry, the bending moments induced by the insertion forces can be altered to reduce the needle deflection. However, the tissue separation location also affects the tissue contact inside the needle groove, potentially reducing the tissue sampling length. A multi-bevel needle tip geometry with the tissue separation point below the needle groove face may reduce the needle deflection while maintaining a long tissue sampling length. Results from this study can guide needle tip design to enable the precise needle deployment and adequate tissue sampling for the needle biopsy procedures.

Using spatial tracking with magnetic resonance imaging/ultrasound-guided biopsy to identify unilateral prostate cancer

OBJECTIVES

To create reliable predictive metrics of unilateral disease using spatial tracking from a fusion device, thereby improving patient selection for hemi-gland ablation of prostate cancer.

PATIENTS AND METHODS

We identified patients who received magnetic resonance imaging (MRI)/ultrasound-guided biopsy and radical prostatectomy at a single institution between 2011 and 2018. In addition to standard clinical features, we extracted quantitative features related to biopsy core and MRI target locations predictive of tumour unilaterality. Classification and Regression Tree (CART) analysis was used to create a decision tree (DT) for identifying cancer laterality. We evaluated concordance of model-determined laterality with final surgical pathology.

RESULTS

A total of 173 patients were identified with biopsy coordinates and surgical pathology available. Based on CART analysis, in addition to biopsy- and MRI-confirmed disease unilaterality, patients should be further screened for cancer detected within 7 mm of midline in a 40 mL prostate, which equates to the central third of any-sized prostate by radius. The area under the curve for this DT was 0.82. Standard diagnostics and the DT correctly identified disease laterality in 73% and 80% of patients, respectively (P = 0.13). Of the patients identified as unilateral by standard diagnostics, 47% had undetected contralateral disease or were otherwise incorrectly identified. This error rate was reduced to 17% (P = 0.01) with the DT.

CONCLUSION

Using spatial tracking from fusion devices, a DT was more reliable for identifying laterality of prostate cancer compared to standard diagnostics. Patients with cancer detected within the central third of the prostate by radius are poor hemi-gland ablation candidates due to the risk of midline extension of tumour.

Joint Prostate Cancer Detection and Gleason Score Prediction in mp-MRI via FocalNet

Multi-parametric MRI (mp-MRI) is considered the best non-invasive imaging modality for diagnosing prostate cancer (PCa). However, mp-MRI for PCa diagnosis is currently limited by the qualitative or semi-quantitative interpretation criteria, leading to inter-reader variability and a suboptimal ability to assess lesion aggressiveness. Convolutional neural networks (CNNs) are a powerful method to automatically learn the discriminative features for various tasks, including cancer detection. We propose a novel multi-class CNN, FocalNet, to jointly detect PCa lesions and predict their aggressiveness using Gleason score (GS). FocalNet characterizes lesion aggressiveness and fully utilizes distinctive knowledge from mp-MRI. We collected a prostate mp-MRI dataset from 417 patients who underwent 3T mp-MRI exams prior to robotic-assisted laparoscopic prostatectomy. FocalNet was trained and evaluated in this large study cohort with fivefold cross validation. In the free-response receiver operating characteristics (FROC) analysis for lesion detection, FocalNet achieved 89.7% and 87.9% sensitivity for index lesions and clinically significant lesions at one false positive per patient, respectively. For the GS classification, evaluated by the receiver operating characteristics (ROC) analysis, FocalNet received the area under the curve of 0.81 and 0.79 for the classifications of clinically significant PCa (GS ≥ 3 + 4) and PCa with GS ≥ 4 + 3, respectively. With the comparison to the prospective performance of radiologists using the current diagnostic guideline, FocalNet demonstrated comparable detection sensitivity for index lesions and clinically significant lesions, only 3.4% and 1.5% lower than highly experienced radiologists without statistical significance.

Can Extraprostatic Extension Be Predicted by Tumor-Capsule Contact Length in Prostate Cancer? Relationship With International Society of Urological Pathology Grade Groups

OBJECTIVE. The objective of our study was to evaluate the relationship between the tumor-capsule contact length, defined as tumor contact length (TCL), and extraprostatic extension (EPE) using the MRI-based TCL measurements and the real TCL measurements from pathology and to determine whether the International Society of Urological Pathology (ISUP) grade group of the tumors influenced this relationship. MATERIALS AND METHODS. In this retrospective study, we reviewed prostate multiparametric MRI (mpMRI) studies performed between 2012 and 2018 of 1576 patients and found that 134 patients also underwent radical prostatectomy (RP) after mpMRI. Finally, 86 patients with index lesions in contact with the prostate capsule in RP specimens were enrolled in the study. ROC analysis was used to evaluate the cutoff values of TCLs measured at pathology and TCLs measured on MRI in terms of EPE according to ISUP grade groups. RESULTS. There was no statistically significant cutoff value for pathology-based TCL measurements in individual ISUP grade groups and subgroups. Although not statistically significant, pathology-based TCL cutoff values decreased (from 21.0 to 11.0 mm) as ISUP grade group increased in terms of EPE positivity. When the relationship between MRI-based TCL measurements and EPE was considered, statistically significant cutoff values (range, 14.5-16.6 mm) could be determined in many groups and subgroups with low ISUP grades (sensitivity, 66.7-100%; specificity, 52.8-93.0%; p = 0.006-0.042). However, no statistically significant cutoff value was found for high ISUP grades. CONCLUSION. ISUP grade groups may have an effect on the TCL-EPE relationship. When the MRI-based TCL and EPE relationship is evaluated independent of ISUP grade group, a cutoff value around 15-16 mm may be usable to predict EPE.

MRI-Fusion Targeted vs. Systematic Prostate Biopsy-How Does the Biopsy Technique Affect Gleason Grade Concordance and Upgrading After Radical Prostatectomy?

Introduction: MRI-targeted biopsy (TB) increases overall prostate-cancer (PCa) detection-rates and decreases the risk of insignificant PCa detection. However, the impact of these findings on the definite pathology after radical prostatectomy (RP) is under debate. Materials and Methods: Between 01/2014 and 12/2018, 366 patients undergoing prostate biopsy and RP were retrospectively analyzed. The correlation between biopsy Gleason-score (highest Gleason-score in a core) and the RP Gleason-score in patients undergoing systematic biopsy (SB-group) (n = 221) or TB+SB (TB-group, n = 145) was tested using the ISUP Gleason-group grading (GGG, scale 1-5). Sub analyses focused on biopsy GGG 1 and GGG ≥ 2. Results: Proportions of biopsy GGG 1-5 in the SB-group and TB-group were 24.4, 37.6, 19, 10.9, 8.1% and 13.8, 43.4, 24.2, 13.8, 4.8%, respectively (p = 0.07). Biopsy and pathologic GGG were concordant in 108 of 221 (48.9%) in SB- and 74 of 145 (51.1%) in TB-group (p = 0.8). Gleason upgrading was recorded in 33.5 and 31.7% in SB- vs. TB-group (p = 0.8). Patients with biopsy GGG 1 undergoing RP showed an upgrading in 68.5%(37/54) in SB- and 75%(15/20) in TB-group (p = 0.8). In patients with biopsy GGG ≥ 2 concordance increased for both biopsy approaches (54.5 vs. 55.2% for SB- vs. TB-group, p = 0.9). Discussion: Irrespective of differences in PCa detection-rates between TB- and SB-groups, no significant differences in GGG concordance and upgrading between patients of both groups undergoing biopsy, followed by RP, were recorded. Concordance rates increased in men with biopsy GGG ≥ 2. TB seems to detect more patients with PCa without a difference in concordance with final pathology.

Concordance Between Biopsy and Radical Prostatectomy Pathology in the Era of Targeted Biopsy: A Systematic Review and Meta-analysis

CONTEXT

Multiparametric magnetic resonance imaging (mpMRI)-targeted transrectal prostate biopsy (TBx) may better predict pathology at radical prostatectomy than systematic transrectal prostate biopsy (SBx).

OBJECTIVE

To assess concordance between biopsy and radical prostatectomy pathology in men undergoing a TBx as compared with those undergoing an SBx.

EVIDENCE ACQUISITION

Four electronic databases (Ovid MEDLINE, Ovid EMBASE, the Cochrane Library [Wiley], and EBSCHOHost) were searched from inception until July 2018. Studies were included if they were published after 2012, conducted both SBx and TBx, and compared the biopsy results with final pathology after radical prostatectomy for ≥50 patients. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were utilized. Bias was appraised using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool.

EVIDENCE SYNTHESIS

Our search yielded 10 studies including 1215 men. However, our inclusion criteria applied only to a proportion of men included in these studies. The median age was 65 yr and the median prostate-specific antigen level was 7.2 ng/ml. In the eight studies examining upgrading at prostatectomy, pathology from SBx was significantly more likely to be upgraded relative to TBx (odds ratio [OR] 2.47, 95% confidence interval [CI] 1.48-4.14, p =  0.001). We found no significant difference in downgrading (OR 1.13, 95% CI 0.48-2.67, p =  0.783) between TBx and SBx. For both biopsy-naïve men and men with a prior negative biopsy, results from SBx were more likely to be upgraded than TBx at prostatectomy (OR 1.6 [95% CI 1.02-2.27, p <  0.001] and OR 4.23 [95% CI 1.68-8.48, p =  0.003], respectively).

CONCLUSIONS

Pathologic upgrading at prostatectomy was less likely with mpMRI-targeted biopsy versus systematic biopsy alone, without concurrent increase in downgrading. This increased accuracy should improve confidence in management decisions based on MRI-targeted biopsy pathology.

PATIENT SUMMARY

We reviewed the ability of multiparametric magnetic resonance imaging -targeted biopsy to predict cancer grade at radical prostatectomy. We found that targeted biopsy provides more accurate assessment of Gleason score at prostatectomy than systematic biopsy.

The Use of Multiparametric Magnetic Resonance Imaging (mpMRI) in the Detection, Evaluation, and Surveillance of Clinically Significant Prostate Cancer (csPCa)

PURPOSE OF REVIEW

With the long-standing controversy surrounding the use of prostate-specific antigen (PSA) for the detection, evaluation, and surveillance of prostate cancer, there is a need for a minimally invasive technique to identify and risk-stratify these patients. Additionally, in an effort to reduce the number of unnecessary biopsies and identify clinically significant prostate cancer (csPCa), there has been a shift in practice towards the use of multiparametric magnetic resonance imaging (mpMRI) in conjunction with decision-making regarding prostate cancer diagnosis and management. In the current review, we summarize the data regarding the use of mpMRI in the detection, evaluation, and surveillance of csPCa.

RECENT FINDINGS

Recent prospective clinical trials have determined that a pre-biopsy mpMRI may rule out insignificant prostate cancers, thereby reducing the number of patients who require a biopsy. The anatomic information gathered from these pre-biopsy mpMRI performed during MRI fusion biopsy in csPCa increases the accuracy of pathologic staging in terms of Gleason scores. In regard to active surveillance, prospective trials suggest little to no clinical utility for mpMRI and fusion biopsy in the surveillance of prostate cancer despite conflicting findings from retrospective studies. Recent trials suggest that mpMRI can play an important role in the detection and evaluation of csPCa. The ideal role for mpMRI in active surveillance remains limited.

The use of prostate MR for targeting prostate biopsies

Management of prostate cancer relies heavily on accurate risk stratification obtained through biopsies, which are conventionally performed under transrectal ultrasound (TRUS) guidance. Yet, multiparametric MRI has grown to become an integral part of the care of males with known or suspected prostate cancer. This article will discuss in detail the different MRI-targeted biopsy techniques, their advantages and disadvantages, and the impact they have on patient management.

Is There Still a Need for Repeated Systematic Biopsies in Patients with Previous Negative Biopsies in the Era of Magnetic Resonance Imaging-targeted Biopsies of the Prostate?

BACKGROUND

The role of targeted prostate biopsies (TBs) in patients with cancer suspicious lesions on multiparametric magnetic resonance imaging (mpMRI) following negative systematic biopsies (SBs) is undebated. However, whether they should be combined with repeated SBs remains unclear.

OBJECTIVE

To evaluate the value of repeated SBs in addition to TBs in patients with a prior negative SB and a persistent suspicion of prostate cancer (PCa).

DESIGN, SETTING, AND PARTICIPANTS

A prospective study as part of a multicenter randomized controlled trial conducted between 2014 and 2017, including 665 men with a prior negative SB and a persistent suspicion of PCa (suspicious digital rectal examination and/or prostate-specific antigen >4.0ng/ml).

INTERVENTION

All patients underwent 3T mpMRI according to Prostate Imaging Reporting and Data System (PI-RADS) v2. Patients with PI-RADS ≥3 were randomized 1:1:1 for three TB techniques: MRI-TRUS fusion TB (FUS-TB), cognitive registration fusion TB (COG-TB), or in-bore MRI TB. FUS-TB and COG-TB were combined with repeated SBs.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Clinically significant prostate cancer (csPCa) was defined as Gleason ≥3+4. Differences in detection rates of csPCa, clinically insignificant PCa (cisPCa), and overall PCa between TBs (FUS-TB and COG-TB) and repeated SBs were compared using McNemar's test.

RESULTS AND LIMITATIONS

In the 152 patients who underwent both TB and SB, PCa was detected by TB in 47% and by SB in 32% (p<0.001, 95% confidence interval [CI]: 6.0-22%). TB detected significantly more csPCa than SB (32% vs 16%; p<0.001, 95% CI: 11-25%). Clinically significant PCa was missed by TB in 1.3% (2/152). Combining SB and TB resulted in detection rate differences of 6.0% for PCa, 5.0% for cisPCa, and 1.0% for csPCa compared with TB alone.

CONCLUSIONS

In case of a persistent suspicion of PCa following a negative SB, TB detected significantly more csPCa cases than SB. The additional value of SB was limited, and only 1.3% of csPCa would have been missed when SB had been omitted.

PATIENT SUMMARY

We evaluated the role of systematic biopsies and magnetic resonance imaging (MRI)-targeted biopsies for the diagnosis of prostate cancer in patients with prior negative systematic biopsies. MRI-targeted biopsies perform better in detecting prostate cancer in these patients. The value of repeated systematic biopsies is limited.

Magnetic resonance imaging-guided targeted biopsy in risk classification among patients on active surveillance: A diagnostic meta-analysis

BACKGROUND

The aim of this study was to assess the sensitivity and accuracy of magnetic resonance imaging-guided targeted biopsy (MRI-TB) in patients undergoing active surveillance (AS) procedure.

METHODS

We searched databases to identify relevant studies which compared MRI-TB with systemic biopsy for diagnosing prostate cancer in patients on AS. Outcomes included sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), area under the curve (AUC) and publication bias of AS group, confirmatory biopsy group and follow-up biopsy group.

RESULTS

Fourteen articles involving 1693 patients were included. In AS group, the sensitivity was 0.62 (95% confidence interval [CI], 0.57-0.68), specificity was 0.89 (95% CI, 0.87-0.90), NLR was 0.43 (0.31-0.60), PLR was 4.90 (3.50-6.86), DOR was 12.75 (7.22-22.51), and AUC was 0.8645. In confirmatory biopsy group, the sensitivity was 0.67 (0.59-0.74), specificity was 0.89 (0.86-0.91), NLR was 0.42 (0.27-0.65), PLR was 4.94 (3.88-6.30), DOR was 14.54 (9.60-22.02), and AUC was 0.8812. In follow-up biopsy group, the sensitivity was 0.35 (0.22-0.51), specificity was 0.88 (0.82-0.92), NLR was 0.76 (0.52-1.11), PLR was 3.06 (1.71-5.50), DOR was 4.41 (2.15-9.03), and AUC was 0.8367.

CONCLUSION

MRI-TB has a moderate-to-high diagnostic accuracy for diagnosing and reclassifying patients on AS with high specificity and AUC value under the SROC curve.

Targeted Prostate Biopsy Gleason Score Heterogeneity and Implications for Risk Stratification

OBJECTIVES

To quantify Gleason score (GS) heterogeneity within multiparametric magnetic resonance imaging (MRI)-targeted prostate biopsies and to determine impact on National Comprehensive Cancer Network (NCCN) risk stratification.

METHODS

An Institutional Review Board-approved retrospective study was performed on men who underwent Artemis (MRI-transrectal-ultrasound fusion) targeted biopsy (TB) for suspected prostate cancer between 2012 and 2015. Intratarget heterogeneity was defined as a difference in GS between 2 cores within a single target in patients with ≥2 positive cores. Prostate specific antigen, maximum tumor diameter, apparent diffusion coefficient, MRI suspicion score, prostate volume, systematic biopsy (SB) GS, and T-stage were analyzed for correlation with heterogeneity. Changes in NCCN risk based on high versus low GS on TB, SB alone, and SB+TB were compared.

RESULTS

Fifty-three patients underwent TB of 73 suspected lesions. Seventy percent (51/73) had ≥2 positive cores, thus meeting inclusion criteria for heterogeneity analysis. Fifty-five percent (28/51) of qualifying targets showed GS heterogeneity. None of the evaluated factors showed a significant relationship with heterogeneity. NCCN low-risk, intermediate-risk, and high-risk groups were 30%, 49%, and 21%, respectively, with SB alone. Adding low GS TB to SB resulted in 17%, 55%, 28% in each risk group, while using high GS+SB resulted in 4%, 54%, and 42%. Overall, the addition of TB resulted in higher NCCN risk groups in 38% of cases.

CONCLUSIONS

Over half of multiparametric MRI-defined targets demonstrated GS heterogeneity. The addition of high GS from TB leads to risk inflation compared with using SB alone. Further research is needed on how to integrate these findings into current risk stratification models and clinical practice.

How Often is the Dynamic Contrast Enhanced Score Needed in PI-RADS Version 2?

BACKGROUND

Prostate imaging reporting and data system version 2 (PI-RADS v2) relegates dynamic contrast enhanced (DCE) imaging to a minor role. We sought to determine how often DCE is used in PI-RADS v2 scoring.

MATERIALS AND METHODS

We retrospectively reviewed data from 388 patients who underwent prostate magnetic resonance imaging and subsequent biopsy from January 2016 through December 2017. In accordance with PI-RADS v2, DCE was deemed necessary if a peripheral-zone lesion had a diffusion-weighted imaging score of 3, or if a transition-zone lesion had a T2 score of 3 and diffusion-weighted imaging experienced technical failure. Receiver operating characteristic curve analysis assessed the accuracy of prostate-specific antigen density (PSAD) at different threshold values for differentiating lesions that would be equivocal with noncontrast technique. Accuracy of PSAD was compared to DCE using McNemar's test.

RESULTS

Sixty-nine lesions in 62 patients (16%) required DCE for PI-RADS scoring. Biopsy of 10 (14%) of these lesions showed clinically significant cancer (Gleason score ≥7). In the subgroup of patients with equivocal lesions, those with clinically significant cancer had significantly higher PSADs than those with clinically insignificant lesions (means of 0.18 and 0.13 ng/mL/mL, respectively; P= 0.038). In this subgroup, there was no statistical difference in accuracy in determining clinically significant cancer between a PSAD threshold value of 0.13 and DCE (P= 0.25).

CONCLUSIONS

Only 16% of our patients needed DCE to generate the PI-RADS version 2 score, raising the possibility of limiting the initial screening prostate MRI to a noncontrast exam. PSAD may also be used to further decrease the need for or to replace DCE altogether.

The Impact of 68Ga-PSMA PET/CT and PET/MRI on the Management of Prostate Cancer

Prostate-specific membrane antigen (PSMA) is a transmembrane protein with significantly increased expression in the cells and metastases of prostate carcinoma (CaP). PSMA-expression correlates with higher serum levels of prostate-specific antigen (PSA) and a higher Gleason score (GS). This finding has led to the development of novel imaging modalities such as 68Ga-/18F-labeled PSMA positron emission tomography/computed tomography (PET/CT) and positron emission tomography/magnetic resonance imaging (PET/MRI). This article reviews the literature pertaining to various new imaging technologies for the management of CaP. PSMA positron emission tomography/computed tomography appears to be an excellent diagnostic tool, that may drastically impact the management of a large number of patients with primary and recurrent CaP.

Cancer core length from targeted biopsy: an index of prostate cancer volume and pathological stage

OBJECTIVE

To study the relationship of maximum cancer core length (MCCL), on targeted biopsy (TB) of magnetic resonance imaging (MRI)-visible index lesions, to volume of that tumour found at radical prostatectomy (RP).

PATIENTS AND METHODS

In all, 205 men undergoing fusion biopsy and RP were divided into two groups: 136 in whom the MCCL came from an index MRI-visible lesion (TB) and 69 in whom MCCL came from a non-targeted lesion (non-targeted biopsy [NTB]). MRI was 3-T multi-parametric and biopsy was via MRI-ultrasonography fusion.

RESULTS

In the TB group, MCCL correlated with volume of clinically significant index tumours (ρ = 0.44-0.60, P < 0.01). The correlation was similar for first and repeat biopsy and for transition and peripheral zone lesions (ρ = 0.42-0.49, P < 0.01). No correlations were found in the NTB group. TB MCCL (6-10 and >10 mm) and MRI lesion diameter (>20 mm) were independently associated with tumour volume. TB MCCLs >10 mm and Gleason scores >7 were each associated with pathological T3 disease (odds ratios 5.73 and 5.04, respectively), but MRI lesion diameter lesion was not.

CONCLUSIONS

MCCL on a TB from an MRI-visible lesion is an independent predictor of both cancer volume and pathological stage. This relationship does not exist for MCCL from a NTB core. Quantifying CCL on MRI-TBs may have a value, not previously described, to risk-stratify patients with prostate cancer before treatment.

Downgrading of Grade Group After Radical Prostatectomy: Comparison of Multiparametric Magnetic Resonance Imaging Guided Fusion Biopsy and Standard 12-Core Biopsy

OBJECTIVE

To analyze the factors associated with Grade group (GG) downgrading post-radical prostatectomy.

PATIENTS AND METHODS

We performed a retrospective analysis of 536 patients who underwent robot-assisted laparoscopic radical prostatectomy from February 2014 to October 2015. We have analyzed the clinical, radiological, and pathologic factors associated with GG downgrading in final pathology. Downgrading was defined as those patients who downgraded from GG 3, 4, or 5 on biopsy to GG 1 or 2 on final pathology as well as patients who downgraded from GG 2 on biopsy to GG 1 on final pathology. Categorical values were compared with chi-square and Fischer's exact tests. Mann-Whitney U and Kruskal-Wallis were used for analysis of independent variables associated with GG downgrading.

RESULTS

Ninety-three patients underwent fusion biopsy (FB) and 443 underwent the standard 12 core biopsy. Baseline clinical characteristics were similar between the 2 groups except for race (P = .009). Downgrading was observed in 76 patients (14.1%). Rate of downgrading was higher in the FB group (n = 22, 23.7% vs n = 54, 12.2%, P = .008). In multivariable logistic regression analysis, FB (OR:2.39, P = .004) and maximum percentage of core involvement (OR:1.01, P = .013) were associated with downgrading after robot-assisted laparoscopic radical prostatectomy. After 1:2 propensity score matching, FB was still associated with an increased rate of downgrading (P = .034). Downgrading had no significant effect on pathologic outcome.

CONCLUSION

FB and maximum percentage of core involvement are the only factors associated with GG downgrading in final pathology. However, downgrading did not influence surgical outcome.

The added value of systematic biopsy in men with suspicion of prostate cancer undergoing multiparametric MRI-targeted biopsy

PURPOSE

Incorporation of multiparametric magnetic resonance imaging (mpMRI) and targeted biopsy (TBx) in the diagnostic pathway for prostate cancer (CaP) is rapidly becoming common practice. In men with a prebiopsy positive mpMRI a TBx only approach, thereby omitting transrectal ultrasound-guided systematic biopsy (SBx), has been postulated. In this study we evaluated the additional clinical relevance of SBx in men with a positive prebiopsy mpMRI (Prostate Imaging Reporting and Data System [PI-RADS] ≥ 3) undergoing TBx for CaP detection, Gleason grading and CaP localization.

MATERIAL AND METHODS

Prospective data of 255 consecutive men with a prebiopsy positive mpMRI (PI-RADS ≥ 3) undergoing 12-core SBx and subsequent MRI-transrectal ultrasound fusion TBx in 2 institutions between 2015 and 2018 was obtained. The detection rate for significant CaP (Gleason score [GS] ≥ 3 + 4) for TBx and SBx were compared. The rate of potentially missed significant CaP by a TBx only approach was determined and GS concordance and CaP localization by TBx and SBx was evaluated.

RESULTS

TBx yielded significant CaP in 113 men (44%) while SBx yielded significant CaP in 110 men (43%) (P = 0.856). Insignificant CaP was found in 21 men (8%) by TBx, while SBx detected 34 men (13%) with insignificant CaP (P = 0.035). A TBx only approach, omitting SBx, would have missed significant CaP in 13 of the 126 men (10%) with significant CaP on biopsy. Ten of the 118 men (8%), both positive on TBx and SBx, were upgraded in GS by SBx while 11 men (9%) had higher maximum tumor core involvement on SBx. Nineteen of the 97 men (20%) with significant CaP in both TBx and SBx were diagnosed with unilateral significant CaP on mpMRI and TBx while SBx demonstrated bilateral significant CaP.

CONCLUSIONS

In men with a prebiopsy positive mpMRI, TBx detects high-GS CaP while reducing insignificant CaP detection as compared to SBx. SBx and TBx as stand-alone missed significant CaP in 13% and 10% of the men with significant CaP on biopsy, respectively. A combination of SBx and TBx remains necessary for the most accurate assessment of detection, grading, tumor core involvement, and localization of CaP.

Risk of upgrading from prostate biopsy to radical prostatectomy pathology: Is magnetic resonance imaging-guided biopsy more accurate?

Background: This study compared magnetic resonance imaging-guided biopsy (MRI-GB) and transrectal ultrasound guided biopsy (TRUS-GB) with the final histology of the radical prostatectomy (RP) specimen.

Methods: Our subjects were 229 patients with prostate cancer (PCa), proven histopathologically using MRI-GB or TRUS-GB, who underwent RP at our center between December 2015 and December 2016. The main group included 92 patients who underwent MRI-GB and the control group included 137 patients who underwent 12-core TRUS-GB. Histological findings for RP specimens were compared with those from biopsies. We also evaluated predictors of upgraded Gleason score (GS), using uni- and multivariate analyses.

Results: Upgraded GS between biopsy and RP specimen occurred to 22.7% (52/229) of the cohort overall. In univariate analysis, prostate-specific antigen density (PSAD) (P<0.001), prostate volume (PV) < 30 ml (P<0.001), biopsy modality (P=0.027), biopsy GS (P=0.032) and measured MRI lymph node metastasis (P=0.018) were prognostic factors. Multivariate logistic regression analysis showed PV < 30 ml (P<0.001) and biopsy modality (P=0.001) were independent predictors of upgraded GS.

Conclusions: MRI-GB may enhance the diagnostic accuracy of prostate cancer detection in final histopathology with lower rate of upgraded GS than TRUS-GB. Also, PV < 30 ml and biopsy modality were independent predictors of upgraded GS.