Multiparametric Magnetic Resonance/Ultrasound Fusion Prostate Biopsy: Number and Spatial Distribution of Cores for Better Index Tumor Detection and Characterization

Enhancing Prostate Cancer Diagnosis: Artificial Intelligence-Driven Virtual Biopsy for Optimal Magnetic Resonance Imaging-Targeted Biopsy Approach and Gleason Grading Strategy

An optimal approach to magnetic resonance imaging fusion targeted prostate biopsy (PBx) remains unclear (number of cores, intercore distance, Gleason grading [GG] principle). The aim of this study was to develop a precise pixel-wise segmentation diagnostic artificial intelligence (AI) algorithm for tumor detection and GG as well as an algorithm for virtual prostate biopsy that are used together to systematically investigate and find an optimal approach to targeted PBx. Pixel-wise AI algorithms for tumor detection and GG were developed using a high-quality, manually annotated data set (slides n = 442) after fast-track annotation transfer into segmentation style. To this end, a virtual biopsy algorithm was developed that can perform random biopsies from tumor regions in whole-mount whole-slide images with predefined parameters. A cohort of 115 radical prostatectomy (RP) patient cases with clinically significant, magnetic resonance imaging-visible tumors (n = 121) was used for systematic studies of the optimal biopsy approach. Three expert genitourinary (GU) pathologists (Y.T., A.P., A.Q.) participated in the validation. The tumor detection algorithm (aware version sensitivity/specificity 0.99/0.90, balanced version 0.97/0.97) and GG algorithm (quadratic kappa range vs pathologists 0.77-0.78) perform on par with expert GU pathologists. In total, 65,340 virtual biopsies were performed to study different biopsy approaches with the following results: (1) 4 biopsy cores is the optimal number for a targeted PBx, (2) cumulative GG strategy is superior to using maximal Gleason score for single cores, (3) controlling for minimal intercore distance does not improve the predictive accuracy for the RP Gleason score, (4) using tertiary Gleason pattern principle (for AI tool) in cumulative GG strategy might allow better predictions of final RP Gleason score. The AI algorithm (based on cumulative GG strategy) predicted the RP Gleason score of the tumor better than 2 of the 3 expert GU pathologists. In this study, using an original approach of virtual prostate biopsy on the real cohort of patient cases, we find the optimal approach to the biopsy procedure and the subsequent GG of a targeted PBx. We publicly release 2 large data sets with associated expert pathologists' GG and our virtual biopsy algorithm.

Utility of positive core number on MRI-ultrasound fusion targeted biopsy in combination with PI-RADS scores for predicting unexpected extracapsular extension of clinically localized prostate cancer

OBJECTIVES

To evaluate the utility of magnetic resonance imaging (MRI) and MRI-ultrasound fusion targeted biopsy (TB) for predicting unexpected extracapsular extension (ECE) in clinically localized prostate cancer (CLPC).

METHODS

This study enrolled 89 prostate cancer patients with one or more lesions showing a Prostate Imaging-Reporting and Data System (PI-RADS) score ≥3 but without morphological abnormality in the prostatic capsule on pre-biopsy MRI. All patients underwent TB and systematic biopsy followed by radical prostatectomy (RP). Each lesion was examined by 3-core TB, taking cores from each third of the lesion. The preoperative variables predictive of ECE were explored by referring to RP specimens in the lesion-based analysis.

RESULTS

Overall, 186 lesions, including 81 (43.5%), 73 (39.2%), and 32 (17.2%) with PI-RADS 3, 4, and 5, respectively, were analyzed. One hundred and twenty-two lesions (65.6%) were diagnosed as cancer on TB, and ECE was identified in 33 (17.7%) on the RP specimens. The positive TB core number was ≤2 in 129 lesions (69.4%) and three in 57 lesions (30.6%). On the multivariate analysis, PI-RADS ≥4 (p = 0.049, odds ratio [OR] = 2.39) and three positive cores on TB (p = 0.005, OR = 3.07) were independent predictors of ECE. Lesions with PI-RADS ≥4 and a positive TB core number of 3 had a significantly higher rate of ECE than those with PI-RADS 3 and a positive TB core number ≤2 (37.5% vs. 7.8%, p < 0.001).

CONCLUSIONS

Positive TB core number in combination with PI-RADS scores is helpful to predict unexpected ECE in CLPC.

Does a large prostate size, small lesion volume, or long needle distance from the probe to the lesion reduce magnetic resonance imaging-targeted cancer detection?

Background

We aimed to evaluate whether large prostate size, small lesion volume, or long lesion distance from the ultrasound probe tip would decrease cancer detection in transrectal magnetic resonance imaging (MRI)-targeted biopsies.

Materials and methods

Patients who underwent MRI-targeted biopsy at our institution between May 2017 and August 2019 were enrolled in a prospective database. Three to 5 cores were obtained from ≥2 prostate imaging reporting and data system v2 lesions. A multivariable model was created that included needle distance to the lesion, prostate specific antigen, prostate imaging reporting and data system, lesion volume, and prostate volume.

Results

A total of 377 patients with 533 lesions underwent a biopsy during the study period. A total of 233 (44%) lesions were positive for prostate cancer, and 173 (32%) lesions had clinically significant prostate cancer. The mean needle distance to the lesion was 11.7 mm (interquartile range, 7.6-15.5 mm). The likelihood of obtaining a positive core on biopsy decreased as the distance from the ultrasound probe increased for all prostate cancers and clinically significant prostate cancer (p = 0.018 and p = 0.004, respectively). Every 10 mm from the rectum, there was an 8%-10% decrease in the rate of cancer detection. Similarly, as the prostate volume increased, the odds of obtaining a positive core also decreased (p = 0.039). There was no significant association between the lesion size and amount of cancer obtained on biopsy.

Conclusions

Our data showed that transrectal MRI-targeted biopsy cancer detection modestly decreased the lesion from the ultrasound probe and with a large prostate volume but could not prove that lesion volume was a significant predictor of the amount of cancer detected.

Machine-Learning-Based Tool to Predict Target Prostate Biopsy Outcomes: An Internal Validation Study

The aim of this study is to present a personalized predictive model (PPM) with a machine learning (ML) system that is able to identify and classify patients with suspected prostate cancer (PCa) following mpMRI. We extracted all the patients who underwent fusion biopsy (FB) from March 2014 to December 2019, while patients from August 2020 to April 2021 were included as a validation set. The proposed system was based on the following four ML methods: a fuzzy inference system (FIS), the support vector machine (SVM), k-nearest neighbors (KNN), and self-organizing maps (SOMs). Then, a system based on fuzzy logic (FL) + SVM was compared with logistic regression (LR) and standard diagnostic tools. A total of 1448 patients were included in the training set, while 181 patients were included in the validation set. The area under the curve (AUC) of the proposed FIS + SVM model was comparable with the LR model but outperformed the other diagnostic tools. The FIS + SVM model demonstrated the best performance, in terms of negative predictive value (NPV), on the training set (78.5%); moreover, it outperformed the LR in terms of specificity (92.1% vs. 83%). Considering the validation set, our model outperformed the other methods in terms of NPV (60.7%), sensitivity (90.8%), and accuracy (69.1%). In conclusion, we successfully developed and validated a PPM tool using the FIS + SVM model to calculate the probability of PCa prior to a prostate FB, avoiding useless ones in 15% of the cases.

Optimizing multiparametric magnetic resonance imaging-targeted biopsy and detection of clinically significant prostate cancer: the role of core number and location

PURPOSE

There is currently no consensus regarding the optimal number of multiparametric magnetic resonance imaging (MRI)-targeted biopsy (TB) cores and their spatial distribution within the MRI lesion. We aim to determine the number of TB cores and location needed to adequately detect csPCa.

METHODS

We conducted a retrospective cohort study of 505 consecutive patients undergoing TB for positive MRI lesions defined by a PI-RADS score ≥ 3 between June 2016 and January 2022. Cores chronology and locations were prospectively recorded. The co-primary outcomes were the first core to detect clinically significant prostate cancer (csPCa) and the first highest ISUP grade group. The incremental benefit of each additional core was evaluated. Analysis was then performed by distinguishing central (cTB) and peripheral (pTB) within the MRI lesion.

RESULTS

Overall, csPCa was detected in 37% of patients. To reach a csPCa detection rate of 95%, a 3-core strategy was required, except for patients with PI-RADS 5 lesions and those with PSA density ≥ 0.2 ng/ml/cc who benefited from a fourth TB core. At multivariable analysis, only a PSA density ≥ 0.2 ng/ml/cc was an independent predictive factor of having the highest ISUP grade group on the fourth TB cores (p = 0.03). No significant difference in the cancer detection rate was found between cTB and pTB (p = 0.9). Omitting pTB would miss 18% of all csPCa.

CONCLUSION

A 3-core strategy should be considered for TB to optimize csPCa detection with additional cores needed for PI-RADS 5 lesions and high PSA density. Biopsy cores from both central and peripheral zones are required.

MRI/real-time ultrasound image fusion guided high-intensity focused ultrasound: a prospective comparative and functional analysis of different ablative techniques

BACKGROUND

The aim of this paper was to compare safety and functional outcomes of total, hemi and focal ablation by the latest focal high-intensity focused ultrasound (HIFU) device.

METHODS

This is a prospective study including patients with low to intermediate-risk PCa treated with HIFU by Focal One^® device from 11/2018 to 3/2020. Before the treatment all patients underwent mp-magnetic resonance imaging (MRI) and subsequent MRI/transrectal ultrasound (TRUS) fusion and standard biopsy. Patients were stratified according to the type of ablation: total, hemi- or focal ablation. Functional data (IPSS, Quality of Life [QoL], IIEF-5, maximum flow [Qmax] and post void residual [PVR] at flowmetry) were assessed preoperatively and at 1, 3, 6 and 12 months after treatment. Moreover, the urinary symptoms reported by patients at IPSS questionnaire were divided in "irritative" and "obstructive" and compared.

RESULTS

One hundred patients were enrolled. Median prostate volume and lesion diameter were 46 (IQR 25-75) mL and 10 (IQR 6-13) mm. 15, 50 and 35 patients underwent total, hemi- and focal ablation, respectively. No differences were found between them except for operative time (lower in the focal group, P<0.01). Significant lower incidence of irritative symptoms was identified in the focal group compared to the others (P<0.05 at 1 and 3 months of follow-up). No differences were found among the baseline status and the postoperative assessment in terms of obstructive IPSS items, IIEF-5, QoL, Qmax and PVR (all P value>0.05).

CONCLUSIONS

Our study suggests that patients' specific HIFU tailoring with the MRI/real-time TRUS Guidance by Focal One^® device is able to minimize the side effects of treatment.

A prospective randomized controlled trial comparing target prostate biopsy alone approach vs. target plus standard in naïve patients with positive mpMRI

BACKGROUND

In the era of mpMRI guided target fusion biopsy (FB), the role of concomitant standard biopsy (SB) in naïve patients still remains under scrutiny. The aim of this study was to compare the detection rate (DR) of clinically significant prostate cancer (csPCa) in biopsy naïve patients with positive mpMRI who underwent FB alone (Arm A) vs FB+SB (Arm B). Secondary objectives were to compare the incidence of complications, the overall PCa DR and the biopsy results with final pathological findings after robotic prostatectomy (RARP).

METHODS

This is a single center prospective non-inferiority parallel two arms (1:1) randomized control trial (ISRCTN registry number ISRCTN60263108) which took place at San Luigi Gonzaga University Hospital, Orbassano (Turin, Italy) from 4/2019 to 10/2021. Eligible participants were all adults aged<75 years old, biopsy naïve, with serum PSA<15 ng/mL and positive mpMRI (Pi-Rads V.2>3). FB was performed under ultrasound guidance using the BioJet fusion system; four to six target samples were obtained for each index lesion. SB was performed in accordance with the protocol by Rodríguez-Covarrubias. RARP with total anatomical reconstruction was carried out when indicated. DR of PCa and csPCA (Gleason Score >7) were evaluated. Post-biopsy complications according to Clavien-Dindo were recorded. Concordance between biopsy and RARP pathological findings was evaluated. Fisher's Exact test and Mann-Whitney test were applied; furthermore, Logistic Principal Component Analysis (LogPCA) and Pearson's correlation method, in terms of correlation funnel plots, were performed to explore data in a multivariate way.

RESULTS

201 and 193 patients were enrolled in Arm A and B, respectively. csPCa DR was 60.2% vs. 60.6% in Arm A and B respectively (Δ 0.4%; P=0.93); whilst overall PCa DR was 63.7% vs. 71.0% (Δ 7.3%; P=0.12). However, in a target only setting, the addition of SB homolaterally to the index lesion reaching a non-inferior performance compared to the combined sampling (Δ PCa DR 3%). Although the differences of 7.3% in PCa DR, during RARP were registered similar nerve sparing rate (P=0.89), positive surgical margins (P=0.67) and rate of significant upgrading (P=0.12). LogPCA model showed no distinction between the two cohorts; and Pearson's correlation values turned to be between -0.5 and +0.5. In Arm B, the lesion diameter <10 mm is the only predictive variable of positive SB only for PCa (P=0.04), with an additional value +3% for PCa DR.

CONCLUSIONS

In biopsy naïve patients, FB alone is not inferior to FB+SB in detecting csPCa (Δ csPCa DR 0.4%). Δ 7.3% in overall PCa DR was registered between the two Arms, however the addition of further standard samples homolaterally to mp-MRI index lesion improved the overall PCa DR of FB only sampling (Δ PCa DR 3%). The omission of SB did not influence the post-surgical outcomes in terms of NS approach, PSMr and upgrading/downgrading.

Reconciling Discordance Between Prostate Biopsy Histology and Magnetic Resonance Imaging Suspicion - Implementation of a Quality Improvement Protocol of Imaging Re-review and Reverse-fusion Target Analysis

There is uncertainty with how to proceed when targeted prostate biopsy of suspicious multiparametric magnetic resonance imaging (mpMRI) lesions return without clinically significant prostate cancer (csPCa). While possible, there are error sources that could contribute to such discordance including the mpMRI read, mpMRI-ultrasound fusion, biopsy technique, and histologic classification. Consequences are potentially significant; mistakenly missing csPCa can lead to delays in curative treatment. Conversely, in cases of incorrect mpMRI interpretation, the patient may be subjected to unnecessary workup/burden. At our institution, we implemented a quality improvement (QI) initiative triggered after a discordant case occurs. This multidisciplinary review process incorporates mpMRI re-review and assessment of accurate lesion-sampling, termed "reverse-fusion." Herein, we describe the protocol, present sample cases, and discuss clinical implications.

Development of a novel nomogram to identify the candidate to extended pelvic lymph node dissection in patients who underwent mpMRI and target biopsy only

BACKGROUND

Nowadays a tool able to predict the risk of lymph-node invasion (LNI) in patients underwent target biopsy (TB) only before radical prostatectomy (RP) is still lacking. Our aim is to develop a model based on mp-MRI and target biopsy (TB) alone able to predict the risk of LNI.

METHODS

We retrospectively extracted data of patients with preoperative positive mp-MRI and TB only who underwent RARP with ePLND from April 2014 to March 2020. A logistic regression model was performed to evaluate the impact of pre- and intra-operative factors on the risk of LNI. Model discrimination was assessed using an area under (AUC) the ROC curve. A nomogram, and its calibration plot, to predict the risk of LNI were generated based on the logistic model. A validation of the model was done using a similar cohort.

RESULTS

461 patients were included, of which 52 (11.27) had LNI. After logistic regression analysis and multivariable model DRE, PI-RADS, seminal vesicle invasion, PSA and worst GS at I and II target lesions were significant predictors of LNI. The AUC was 0.74 [0.67-0.81] 95% CI. The calibration plot shows that our model is very close to the ideal one which is in the 95% CI. After the creation of a visual nomogram, the cut-off to discriminate between the risk or not of LNI was set with Youden index at 60 points that correspond to a risk of LNI of 7%. The model applied on a similar cohort shown a LH+ of 2.58 [2.17-2.98] 95% CI.

CONCLUSIONS

Our nomogram for patients undergoing MRI-TB only takes into account clinical stage, SVI at MRI, biopsy Gleason pattern and PSA and it is able to identify patients with risk of LNI when a score higher than 7% is achieved.

Pan-segmental intraprostatic lesions involving mid-gland and apex of prostate (mid-apical lesions): assessing the true value of extreme apical biopsy cores

Objective

When considering increased morbidity of apical biopsies, the added diagnostic value of separate targeting of mid-gland and apical segment of the pan-segmental mid-apical mpMRI prostate cancer (PCa) suspicious lesions was assessed.

Materials and methods

A total of 420 patients with a single mpMRI PCa-suspicious PI-RADS ≥ 3 intraprostatic lesion extending from the mid-gland to the apical segment of the gland underwent transrectal MRI-targeted (TBx) and systematic prostate biopsy. Clinically significant PCa (CsPCa) was defined as Gleason Score (GS) ≥ 3 + 4. PCa detection rates of TBx cores were assessed according to targeted anatomical segments. Finally, the diagnostic values of two theoretical TBx protocols utilizing 1-core (A) vs. 2-cores (B) per anatomical segment were compared.

Results

TBx within the pan-segmental mid-apical lesions yielded 44% of csPCa. After stratification into mid- vs. apical segment of the lesion, csPCa was detected in 36% (mid-gland) and 32% (apex), respectively. Within the patients who had no csPCa detection by mid-gland sampling (64%, n = 270), extreme apical TBx yielded additional 8.1% of csPCa. Comparison of extreme apical TBx strategy B vs. overall PCa detection in our cohort revealed corresponding similar rates of 49 vs.50% and 31 vs.32%, respectively.

Conclusion

Separate analyses of both segments, mid-gland and apex, clearly revealed the diagnostic contribution of apical TBx. Our findings strongly suggest to perform extreme apical TBx even within pan-segmental lesions. Moreover, our results indicate that a higher number of cores sampled from the mid-gland segment might be avoided if complemented with a two-core extreme apical TBx.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00345-022-04006-2.

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.

Comprehensive biomarker profiles and chemometric filtering of urinary metabolomics for effective discrimination of prostate carcinoma from benign hyperplasia

Prostate cancer (PCa) is the most commonly diagnosed cancer in male individuals, principally affecting men over 50 years old, and is the leading cause of cancer-related deaths. Actually, the measurement of prostate-specific antigen level in blood is affected by limited sensitivity and specificity and cannot discriminate PCa from benign prostatic hyperplasia patients (BPH). In the present paper, 20 urine samples from BPH patients and 20 from PCa patients were investigated to develop a metabolomics strategy useful to distinguish malignancy from benign hyperplasia. A UHPLC-HRMS untargeted approach was carried out to generate two large sets of candidate biomarkers. After mass spectrometric analysis, an innovative chemometric data treatment was employed involving PLS-DA classification with repeated double cross-validation and permutation test to provide a rigorously validated PLS-DA model. Simultaneously, this chemometric approach filtered out the most effective biomarkers and optimized their relative weights to yield the highest classification efficiency. An unprecedented portfolio of prostate carcinoma biomarkers was tentatively identified including 22 and 47 alleged candidates from positive and negative ion electrospray (ESI+ and ESI-) datasets. The PLS-DA model based on the 22 ESI+ biomarkers provided a sensitivity of 95 ± 1% and a specificity of 83 ± 3%, while that from the 47 ESI- biomarkers yielded an 88 ± 3% sensitivity and a 91 ± 2% specificity. Many alleged biomarkers were annotated, belonging to the classes of carnitine and glutamine metabolites, C21 steroids, amino acids, acetylcholine, carboxyethyl-hydroxychroman, and dihydro(iso)ferulic acid.

Magnetic Resonance Imaging/Ultrasound Fusion-guided Transperineal Versus Magnetic Resonance Imaging/Ultrasound Fusion-guided Transrectal Prostate Biopsy-A Systematic Review

CONTEXT

Magnetic resonance imaging (MRI)-targeted biopsies have changed the dogma in prostate cancer diagnosis. Biopsies can be performed either transrectally (MRI-guided and transrectal ultrasound fusion transrectal biopsy [MRI-TRUSB]) or transperineally (MRI-guided and transrectal ultrasound fusion transperineal biopsy [MRI-TPB]).

OBJECTIVE

To evaluate the detection and complication rates of MRI-TRUSB and MRI-TPB.

EVIDENCE ACQUISITION

We performed a literature search in PubMed, Scopus, EMBASE, and CENTRAL, and selected randomized controlled trials (RCTs) and observational studies comparing MRI-TRUSB versus MRI-TPB.

EVIDENCE SYNTHESIS

Our search identified 3608 studies; we included five in the qualitative and two in the quantitative synthesis. On per-patient pooled analysis for clinically significant prostate cancer (csPCa), MRI-TPB detection rates were significantly higher (relative risk 1.28 [95% confidence interval {CI} 1.03-1.60], p =  0.03). On a per-lesion analysis, MRI-TPB anterior csPCa detection rates were statistically significantly higher (relative risk 2.46 [95% CI 1.22-4.98], p =  0.01). On a per-lesion analysis, MRI-TPB and MRI-TRUSB overall cancer detection rates were 75% and 81.6% (p= 0.53), and csPCa detection rates were 65.7% and 75.5% (p =  0.40), respectively. MRI-TPB had lower complication rates (odds ratio 2.56 [95% CI 1.14-5.56, p <  0.05]). On Grading of Recommendations Assessment, Development, and Evaluation (GRADE) evaluation, we rated all outcomes as "very low" certainty of the evidence for all outcome measures.

CONCLUSIONS

This review highlights the paucity of good-quality evidence comparing MRI-TPB and MRI-TRUSB. MRI-TPB achieves better detection for csPCa, anterior tumors, and lower infective complications. While RCTs are the highest quality of evidence that can address existing evidence limitations, there are concerns regarding infective complications associated with the MRI-TRUSB. Therefore, the authors propose that researchers and clinicians adopt a pragmatic approach by maintaining prospective databases, internal auditing of the MRI-TPB approach, and comparing these data with historical MRI-TRUSB cohorts.

PATIENT SUMMARY

We looked at the outcomes by comparing magnetic resonance imaging (MRI)-guided and transrectal ultrasound fusion transrectal biopsy with MRI-guided and transrectal ultrasound fusion transperineal biopsy (TPB). The analysis suggests, based on very low certainty evidence, that MRI-TPB has better detection for clinically significant prostate cancer, anterior tumors, and lower complications.

Optimal Number of Systematic Biopsy Cores Used in Magnetic Resonance Imaging/Transrectal Ultrasound Fusion Targeted Prostate Biopsy

Background

In recent years, the effectiveness of magnetic resonance imaging (MRI)-ultrasound fusion targeted biopsy (MRF-TB) has been widely reported. In this study, we assessed the effect of reduction of the number of systematic biopsy (SB) cores on the cancer detection rate (CDR).

Methods

Patients with a high prostate-specific antigen (PSA) level underwent prostate MRI. The Prostate Imaging-Reporting and Data System version 2 (PI-RADS) was then used to rate the lesions. The inclusion criteria were as follows: (1) PSA level between 4.0 and 30.0 ng/mL and (2) patients with one or more lesions on MRI and a PI-RADS score of 3 or more. All enrolled patients were SB naïve or had a history of one or more prior negative SBs. A total of 104 Japanese met this selection criterion. We have traditionally performed 14-core SB following the MRF-TB. In this study, the CDRs of 10-core SB methods, excluding biopsy results at the center of the base and mid-level on both sides, were compared with those of the conventional biopsy method.

Results

We compared CDRs of the 14-core and 10-core SBs used in combination. The overall CDR was 55.8% for the former and 55.8% for the latter, thereby indicating that there was no significant difference (P = 1.00) between the two. In addition, the CDRs of csPCa were 51.9% for the former and 51.1% for the latter, which indicated that there was no significant difference (P = 0.317).

Conclusion

There was no significant difference in the CDR when the number of SB cores to be used in combination was 14 and 10.

Diagnostic Yield of Incremental Biopsy Cores and Second Lesion Sampling for In-Gantry MRI-Guided Prostate Biopsy

BACKGROUND. In-gantry MRI-guided biopsy (MRGB) of the prostate has been shown to be more accurate than other targeted prostate biopsy methods. However, the optimal number of cores to obtain during in-gantry MRGB remains undetermined. OBJECTIVE. The purpose of this study was to assess the diagnostic yield of obtaining an incremental number of cores from the primary lesion and of second lesion sampling during in-gantry MRGB of the prostate. METHODS. This retrospective study included 128 men with 163 prostate lesions who underwent in-gantry MRGB between 2016 and 2019. The men had a total of 163 lesions sampled with two or more cores, 121 lesions sampled with three or more cores, and 52 lesions sampled with four or more cores. A total of 40 men underwent sampling of a second lesion. Upgrade on a given core was defined as a greater International Society of Urological Pathology (ISUP) grade group (GG) relative to the previously obtained cores. Clinically significant prostate cancer (csPCa) was defined as ISUP GG 2 or greater. RESULTS. The frequency of any upgrade was 12.9% (21/163) on core 2 versus 10.7% (13/121) on core 3 (p = .29 relative to core 2) and 1.9% (1/52) on core 4 (p = .03 relative to core 3). The frequency of upgrade to csPCa was 7.4% (12/163) on core 2 versus 4.1% (5/121) on core 3 (p = .13 relative to core 2) and 0% (0/52) on core 4 (p = .07 relative to core 3). The frequency of upgrade on core 2 was higher for anterior lesions (p < .001) and lesions with a higher PI-RADS score (p = .007); the frequency of upgrade on core 3 was higher for apical lesions (p = .01) and lesions with a higher PI-RADS score (p = .01). Sampling of a second lesion resulted in an upgrade in a single patient (2.5%; 1/40); both lesions were PI-RADS category 4 and showed csPCa. CONCLUSION. When performing in-gantry MRGB of the prostate, obtaining three cores from the primary lesion is warranted to optimize csPCa diagnosis. Obtaining a fourth core from the primary lesion or sampling a second lesion has very low yield in upgrading cancer diagnoses. CLINICAL IMPACT. To reduce patient discomfort and procedure times, operators may refrain from obtaining more than three cores or second lesion sampling.

Beyond the Learning Curve of Prostate MRI/TRUS Target Fusion Biopsy after More than 1000 Procedures

OBJECTIVE

To evaluate the learning curve (LC) of two urology residents in the execution of fusion biopsy (FB) in terms of overall prostate cancer (PCa) and clinically significant (cs) PCa detection rate (DR) and according to different characteristics of the lesions on MRI MATERIAL AND METHODS: We analyzed data from our prospective maintained FB database between January 2015 and December 2019. FB was performed using the BioJet fusion system (D&K Technologies, Barum, Germany) with a transrectal or transperineal approach. An ANOVA test was used to evaluate the homogeneity of our cohort. Multivariable linear and logistic regression analysis were used to evaluate the relationship between operator experience and DR for PCa and csPCa. Then, the postprocedural complication rate trend was evaluated.

RESULTS

1005 patients were included. The overall DR of PCa was 61.2% (615/1005) [IC 0.58 - 0.64]; whilst DR for csPCA was 54.6% (549/1005) [IC 0.51 - 0.57]. Operator experience does not seem to influence the DR of overall PCa and csPCa; whilst for lesions <8 mm in diameter, PCa and csPCa DR increased significantly with operator experience (P = 0.048 and P = 0.038, respectively). Postprocedural complications remained stable during the whole study period (P = 0.75).

CONCLUSION

A standardized FB approach turned out to be feasible, safe, and effective since the beginning of the residents' LC. PCa and csPCa DR remained stable, at 60% and 55% respectively, after more than 1,000 biopsies. However, for lesions smaller than 8 mm, at least 100 FB of experience is needed to correctly sample the area.

Naive patients with suspicious prostate cancer and positive multiparametric magnetic resonance imaging (mp-MRI): is it time for fusion target biopsy alone?

Objectives:

To determine if standard biopsy still has a role in the detection of prostate cancer or clinically significant prostate cancer in biopsy-naive patients with positive multiparametric magnetic resonance imaging.

Materials and methods:

We extracted, from our prospective maintained fusion biopsy database, patients from March 2014 to December 2018. The detection rate of prostate cancer and clinically significant prostate cancer and complication rate were analysed in a cohort of patients who underwent fusion biopsy alone (group A) or fusion biopsy plus standard biopsy (group B). The International Society of Urological Pathology grade group determined on prostate biopsy with the grade group determined on final pathology among patients who underwent radical prostatectomy were compared.

Results:

Prostate cancer was found in 249/389 (64.01%) and 215/337 (63.8%) patients in groups A and B, respectively ( P=0.98), while the clinically significant prostate cancer detection rate was 57.8% and 55.1% ( P=0.52). No significant differences in complications were found. No differences in the upgrading rate between biopsy and final pathology finding after radical prostatectomy were recorded.

Conclusions:

In biopsy-naive patients, with suspected prostate cancer and positive multiparametric magnetic resonance imaging the addition of standard biopsy to fusion biopsy did not increase significantly the detection rate of prostate cancer or clinically significant prostate cancer. Moreover, the rate of upgrading of the cancer grade group between biopsy and final pathology was not affected by the addition of standard biopsy.

Level of evidence:

Not applicable for this multicentre audit.

The 2019 Genitourinary Pathology Society (GUPS) White Paper on Contemporary Grading of Prostate Cancer

CONTEXT.—

Controversies and uncertainty persist in prostate cancer grading.

OBJECTIVE.—

To update grading recommendations.

DATA SOURCES.—

Critical review of the literature along with pathology and clinician surveys.

CONCLUSIONS.—

Percent Gleason pattern 4 (%GP4) is as follows: (1) report %GP4 in needle biopsy with Grade Groups (GrGp) 2 and 3, and in needle biopsy on other parts (jars) of lower grade in cases with at least 1 part showing Gleason score (GS) 4 + 4 = 8; and (2) report %GP4: less than 5% or less than 10% and 10% increments thereafter. Tertiary grade patterns are as follows: (1) replace "tertiary grade pattern" in radical prostatectomy (RP) with "minor tertiary pattern 5 (TP5)," and only use in RP with GrGp 2 or 3 with less than 5% Gleason pattern 5; and (2) minor TP5 is noted along with the GS, with the GrGp based on the GS. Global score and magnetic resonance imaging (MRI)-targeted biopsies are as follows: (1) when multiple undesignated cores are taken from a single MRI-targeted lesion, an overall grade for that lesion is given as if all the involved cores were one long core; and (2) if providing a global score, when different scores are found in the standard and the MRI-targeted biopsy, give a single global score (factoring both the systematic standard and the MRI-targeted positive cores). Grade Groups are as follows: (1) Grade Groups (GrGp) is the terminology adopted by major world organizations; and (2) retain GS 3 + 5 = 8 in GrGp 4. Cribriform carcinoma is as follows: (1) report the presence or absence of cribriform glands in biopsy and RP with Gleason pattern 4 carcinoma. Intraductal carcinoma (IDC-P) is as follows: (1) report IDC-P in biopsy and RP; (2) use criteria based on dense cribriform glands (>50% of the gland is composed of epithelium relative to luminal spaces) and/or solid nests and/or marked pleomorphism/necrosis; (3) it is not necessary to perform basal cell immunostains on biopsy and RP to identify IDC-P if the results would not change the overall (highest) GS/GrGp part per case; (4) do not include IDC-P in determining the final GS/GrGp on biopsy and/or RP; and (5) "atypical intraductal proliferation (AIP)" is preferred for an intraductal proliferation of prostatic secretory cells which shows a greater degree of architectural complexity and/or cytological atypia than typical high-grade prostatic intraepithelial neoplasia, yet falling short of the strict diagnostic threshold for IDC-P. Molecular testing is as follows: (1) Ki67 is not ready for routine clinical use; (2) additional studies of active surveillance cohorts are needed to establish the utility of PTEN in this setting; and (3) dedicated studies of RNA-based assays in active surveillance populations are needed to substantiate the utility of these expensive tests in this setting. Artificial intelligence and novel grading schema are as follows: (1) incorporating reactive stromal grade, percent GP4, minor tertiary GP5, and cribriform/intraductal carcinoma are not ready for adoption in current practice.

Diagnostic performance of MRI/TRUS fusion-guided biopsies vs. systematic prostate biopsies in biopsy-naïve, previous negative biopsy patients and men undergoing active surveillance

BACKGROUND

We aimed to assess the detection rate of overall PCa and csPCa, and the clinical impact of MRI/TRUS fusion targeted biopsy (FUSION-TB) compared to TRUS guided systematic biopsy (SB) in patients with different biopsy settings.

METHODS

Three hundred and five patients were submitted to FUSION-TB, divided into three groups: biopsy naïve patients, previous negative biopsies and patients under active surveillance (AS). All patients had a single suspicious index lesion at mpMRI. Within these groups, we enrolled men underwent both to FUSION-TB and SB in the same session. Overall detection rate of PCa and csPCa for the two biopsy methods were compared separately between the three groups of patients.

RESULTS

No differences were observed between the three groups concerning clinical and radiological characteristics. We found no differences in terms of overall PCa detection (66% vs. 63.8%, P=0.617) and csPCa detection (56.4% vs. 51.1%; P=0.225) concerning biopsy naïve patients. In patients previously submitted to a negative biopsy, FUSION-TB showed higher detection rate of csPCa compared to SB alone (41,3% vs. 27% respectively, P=0.038). In patients under AS, no differences were observed between FUSION-TB and SB in terms of overall PCa (50% vs. 73.1%) and csPCa (30.8% vs. 26.9%, respectively; P=0.705) detection.

CONCLUSIONS

Our results suggest that in men with previously negative biopsy, FUSION-TB showed significantly higher diagnostic performance for clinically significant PCa as compared to SB. Combination of FUSION-TB and SB should be recommended in AS population to offer higher chance of csPCa diagnosis.

Diagnostic pathway of the biopsy-naïve patient suspected for prostate cancer: Real-life scenario when multiparametric Magnetic Resonance Imaging is not centralized

INTRODUCTION

We aimed to compare the pathway including multi-parametric Magnetic Resonance Imaging (mpMRI) versus the one without mpMRI in detection of prostate cancer (PCa) when mpMRI is not centralized.

MATERIALS

January 2019-March 2020: prospective data collection of trans-perineal prostate biopsies. Group A: biopsy-naïve patients who underwent mpMRI (at any institution) versus Group B: patients who did not. Within Group A, patients were stratified into those with negative mpMRI (mpMRI-, PIRADS v2.1=1-3, with PSA density <0.15 if PIRADS 3) who underwent standard biopsy (SB), versus those with positive mpMRI (mpMRI+, when PIRADS 3-5, with PSA density>0.15 if PIRADS 3) who underwent cognitive fusion biopsy.

RESULTS

Two hundred and eighty one biopsies were analyzed. 153 patients underwent mpMRI (Group A). 98 mpMRI+ underwent fusion biopsy; 55 mpMRI- underwent SB. 128 Group B patients underwent SB. Overall PCa detection rate was 52.3% vs. 48.4% (Group A vs. B, P=0.5). Non-clinically-significant PCa was detected in 7.8 vs. 13.3% (Group A vs. B, P=0.1). Among the 98 mpMRI+ Group A patients only 2 had non clinically-significant disease. In 55 mpMRI- patients who underwent SB, 10 (18.2%) had clinically-significant PCa. Prostate volume predicted detection of PCa. In Group B, age and PSA predicted PCa. Sensitivity of mpMRI was 75.0% for all PCa, 85.3% for clinically-significant PCa.

CONCLUSION

Higher detection of PCa and lower detection of non-clinically-significant PCa favored mpMRI pathway. A consistent number of clinically-significant PCa was diagnosed after a mpMRI-. Thus, in real-life scenario, mpMRI- does not obviate indication to biopsy when mpMRI is not centralized.

LEVEL OF EVIDENCE

3.

Optimizing MRI-targeted prostate biopsy: the diagnostic benefit of additional targeted biopsy cores

INTRODUCTION

The optimal number of biopsy cores to obtain during MRI-targeted prostate biopsy remains ill-defined. This study sought to determine the optimal number of targeted biopsy cores to obtain from a region of interest to maximize detection of clinically significant prostate cancer.

MATERIALS AND METHODS

Consecutive patients undergoing MRI-targeted prostate biopsy at a single institution that newly implemented a targeted biopsy pathway from May 2017 to February 2018 were prospectively enrolled. Five biopsy cores were obtained and individually analyzed from each region rated ≥3 on PI-RADS v2.0 to determine the incremental diagnostic benefit of each additional targeted biopsy core. Variables associated with increasing Grade Group from the first to fifth biopsy core were assessed.

RESULTS

One hundred and four patients (79% for elevated PSA) were enrolled, 82% of which had a prior biopsy. Men with a PI-RADS >3 lesion were more likely to have pathologic upgrading with additional targeted biopsy cores (OR:4.76; 95% CI:2.34-9.70; P < 0.0001), particularly to Grade Group ≥2 (OR:5.16; 95% CI:2.17-12.29; P = 0.0002), compared to men with PI-RADS 3 lesions. Detection of clinically significant cancer increased from 26% to 44% to 52% when comparing the first, third, and fifth biopsy cores amongst men with a PI-RADS >3 lesion and from 1% to 4% to 9% for PI-RADS 3 lesions. Urinary retention was the most common complication, occurring in 6 (5.7%) patients.

CONCLUSION

Clinically significant prostate cancer detection is improved with increased number of MRI-targeted biopsy cores, particularly for urologists early in their learning curve.

Value of extra-target prostate biopsy for the detection of magnetic resonance imaging-missed adverse pathology according to the Prostate Imaging Reporting and Data System scores: Spatial analysis using magnetic resonance-ultrasound fusion images

OBJECTIVES

To clarify who benefits from extra-target sampling of systematic prostate biopsy to detect magnetic resonance imaging-missed significant cancer and upgrading, when concurrently carried out with magnetic resonance imaging-ultrasound fusion targeted biopsy.

METHODS

Targeted biopsy and systematic biopsy were carried out in 301 men with Prostate Imaging Reporting and Data System scores ≥3. All score ≥3 regions were designated as targets. According to patients' highest Prostate Imaging Reporting and Data System scores, spatial relations between targets and biopsy-proven cancer were investigated to identify magnetic resonance imaging-missed pathology.

RESULTS

Overall, targeted biopsy and systematic biopsy detected significant cancer in 56.5% and 46.5%, respectively (P < 0.001). Significant cancer was detected only by systematic biopsy in 7.0%, and only outside targets in 5.0%. Upgrading by systematic biopsy was observed in 16.3%, and occurred outside targets in 11.0%. On multivariate analysis, the highest Prostate Imaging Reporting and Data System 4 was predictive for significant cancer only outside targets (odds ratio 5.81, P = 0.002) and for upgrading derived from outside targets (odds ratio 2.64, P = 0.012). According to the scores of 3, 4 and 5, significant cancer was identified only outside targets in 1.0%, 11.2% and 2.9%, respectively (P = 0.003 for Prostate Imaging Reporting and Data System 3 vs 4; P = 0.019 for Prostate Imaging Reporting and Data System 4 vs 5), and upgrading occurred in 6.1%, 18.4% and 8.6%, respectively (P = 0.009 and 0.040).

CONCLUSIONS

Men with the highest Prostate Imaging Reporting and Data System score 4 receive the largest benefit from extra-target biopsy for magnetic resonance imaging-missed significant cancer detection and upgrading. In men with a score of 3, less adverse pathology is missed without extra-target biopsy. These findings suggest prostate biopsy strategy could be tailored according to Prostate Imaging Reporting and Data System scores.

MRI-targeted prostate biopsy: key considerations for pathologists

We discuss the role of the pathologist for MRI-targeted prostate biopsy with a focus on specimen processing, reporting of pathological findings and quality assurance in establishing a successful MRI-targeted biopsy programme. The authors discuss the current issues relevant to pathologists regarding MRI-targeted prostate biopsy. In addition, a brief review of the recently published literature was performed using an English literature search on PubMed with a focus on original investigations related to MRI-targeted prostate biopsy. Our search terms included the following: 'prostate cancer', 'pathology', 'histology', 'reporting', 'cores', 'imaging', 'MRI' and 'mpMRI'. Prostate multiparametric magnetic resonance imaging (mp-MRI) and MRI-targeted biopsy has been shown to improve the diagnosis of clinically significant prostatic adenocarcinoma and can affect the management of patients with prostate cancer. The current active surveillance guidelines were based on data from TRUS biopsies and not MRI-targeted biopsies. MRI-targeted biopsy acquires multiple cores of tissue from one or more suspicious lesions found on mp-MRI. The way in which multiple targeted core biopsies obtained from a single image-directed region of interest are analysed and reported can potentially alter the Gleason score and tumour burden as reported on biopsy, which could undoubtedly alter patient management. Pathologists play an important role in the reporting of MRI-targeted prostate biopsies. How we report prostate cancer grade and extent on these biopsies can influence patient management. In addition, the pathologist should be involved in the quality assurance for patients undergoing MRI-targeted prostate biopsy.

Detection of clinically significant prostate cancer in biopsy-naïve men: direct comparison of systematic biopsy, multiparametric MRI- and contrast-ultrasound-dispersion imaging-targeted biopsy

OBJECTIVES

To compare and evaluate a multiparametric magnetic resonance imaging (mpMRI)-targeted biopsy (TBx) strategy, contrast-ultrasound-dispersion imaging (CUDI)-TBx strategy and systematic biopsy (SBx) strategy for the detection of clinically significant prostate cancer (csPCa) in biopsy-naïve men.

PATIENTS AND METHODS

A prospective, single-centre paired diagnostic study included 150 biopsy-naïve men, from November 2015 to November 2018. All men underwent pre-biopsy mpMRI and CUDI followed by a 12-core SBx taken by an operator blinded from the imaging results. Men with suspicious lesions on mpMRI and/or CUDI also underwent MRI-TRUS fusion-TBx and/or cognitive CUDI-TBx after SBx by a second operator. A non-inferiority analysis of the mpMRI- and CUDI-TBx strategies in comparison with SBx for International Society of Urological Pathology Grade Group [GG] ≥2 PCa in any core with a non-inferiority margin of 1 percentage point was performed. Additional analyses for GG ≥2 PCa with cribriform growth pattern and/or intraductal carcinoma (CR/IDC), and GG ≥3 PCa were performed. Differences in detection rates were tested using McNemar's test with adjusted Wald confidence intervals.

RESULTS

After enrolment of 150 men, an interim analysis was performed. Both the mpMRI- and CUDI-TBx strategies were inferior to SBx for GG ≥2 PCa detection and the study was stopped. SBx found significantly more GG ≥2 PCa: 39% (56/142), as compared with 29% (41/142) and 28% (40/142) for mpMRI-TBx and CUDI-TBx, respectively (P < 0.05). SBx found significantly more GG = 1 PCa: 14% (20/142) compared to 1% (two of 142) and 3% (four of 142) with mpMRI-TBx and CUDI-TBx, respectively (P < 0.05). Detection of GG ≥2 PCa with CR/IDC and GG ≥3 PCa did not differ significantly between the strategies. The mpMRI- and CUDI-TBx strategies were comparable in detection but the mpMRI-TBx strategy had less false-positive findings (18% vs 53%).

CONCLUSIONS

In our study in biopsy-naïve men, the mpMRI- and CUDI-TBx strategies had comparable PCa detection rates, but the mpMRI-TBX strategy had the least false-positive findings. Both strategies were inferior to SBx for the detection of GG ≥2 PCa, despite reduced detection of insignificant GG = 1 PCa. Both strategies did not significantly differ from SBx for the detection of GG ≥2 PCa with CR/IDC and GG ≥3 PCa.

The optimal core number and site for MRI-targeted biopsy of prostate? A systematic review and pooled analysis

INTRODUCTION

Prebiopsy multiparametric magnetic resonance imaging (mpMRI) has been increasingly utilized for patients of suspicious prostate cancer (PCa). However, the optimal core number and site for MRI-targeted biopsy have not been clearly elucidated.

EVIDENCE ACQUISITION

A systematic search in Pubmed, Embase and Ovid up to June 2019 was conducted and we identified studies reporting detection details of every MRI-targeted core. The incremental diagnostic value of performing additional cores was pooled on per-lesion analysis. Our secondary outcome concentrated on detection accuracy for cores of different site within one lesion.

EVIDENCE SYNTHESIS

Five studies comprising 2291 patients were identified to elucidate the association between targeted core number and cancer detection rates. Adding the second core to the first one resulted in 19.8% (range: 13.6-26.7%) increase in the detection rate of clinically significant lesions, and adding the third one to the first two resulted in 11.5% (range: 7.8-14.3%) increase. The incremental value of adding the fourth or the fifth core was 6.0% (4.7%, 6.9%) and 4.1% respectively. Four studies arranging MRI-targeted biopsy of more than two cores in well-determined sequences indicated more positive cores with higher cancer grade through center of the lesions.

CONCLUSIONS

Increasing the number of samples per target from one to two, or two to three resulted in a nonnegligible incremental detection rate of clinically significant lesions, while obtaining more than 3 cores per target provided a diminished incremental value. And performing targeted cores accurately through center of the lesions may help improve diagnostic accuracy.

Prospective evaluation of urinary steroids and prostate carcinoma-induced deviation: preliminary results

BACKGROUND

The serum prostate-specific antigen is the most widespread biomarker for prostate disease. Its low specificity for prostatic malignancies is a matter of concern and the reason why new biomarkers for screening purposes are needed. The correlation between altered production of the main steroids and prostate carcinoma (PCa) occurrence is historically known. The purpose of this study is to evaluate the modifications of a comprehensive urinary endogenous steroidal profile (USP) induced by PCa, by multivariate statistical methods.

METHODS

A total of 283 Italian subjects were included in the study, 139 controls and 144 PCa-affected patients. The USP, including 17 steroids and five urinary steroidal ratios, was quantitatively evaluated using gas chromatography coupled with single quadrupole mass spectrometry (GC-MS). The data were interpreted using a chemometric, multivariate approach (intrinsically more sensible to alterations with respect to traditional statistics) and a model for the discrimination of cancer-affected profiles was built.

RESULTS

Two multivariate classification models were calculated, the former including three steroids with the highest statistical significance (e.g. testosterone, etiocholanolone and 7β-OH-DHEA) and PSA values, the latter considering the three steroids' levels only. Both models yielded high sensitivity and specificity scores near to 70%, resulting significantly higher than PSA alone.

CONCLUSIONS

Three USP steroids resulted significantly altered in our PCa population. These preliminary results, combined with the simplicity and low-cost of the analysis, open to further investigation of the potential role of this restricted USP in PCa diagnosis.

Risk of Gleason Score 3+4=7 prostate cancer upgrading at radical prostatectomy is significantly reduced by targeted versus standard biopsy

BACKGROUND

The aim of this study is to evaluate if multiparametric magnetic resonance (mpMRI)-transrectal ultrasound (TRUS) fusion targeted biopsy (TBx) versus untargeted standard biopsy (SBx) may decrease the rate of pathological upgrading of Gleason Score (GS) 3+4 prostate cancer (PCa) at radical prostatectomy (RP). We also evaluated the impact of percent pattern 4 and cribriform glands at biopsy in the risk of GS 3+4=7 upgrading.

METHODS

A total of 301 patients with GS 3+4 PCa on biopsy (159 SBx and 142 TBx) who underwent laparoscopic robot-assisted RP were sequentially enrolled. Histological data from RP sections were used as reference standard. The concordance of biopsy with pathological GS, as well as the GS 3+4 upgrading at RP were evaluated in different univariate and multivariate binary logistic regression models, testing age, PSA, fPSA%, tumor volume, PI-RADS, clinical stage, percentage of Gleason pattern 4 (GP) and/or presence of cribriform sub-type at biopsy.

RESULTS

Of the 301 biopsies, the median of GP 4 was 16% of the tissue. Minimal GP 4 (≤16%) cancers had a significant lower median volume (1.7 mL) than those with GP4 >16% (2.9 mL), (P<0.001). Pathological GS 3+4 was confirmed for 58.8% and 82.2% for SBx and TBx patients, respectively. The rate of upgraded and downgraded GS on SBx versus TBx was 38.8% vis. 16.7% and 1.8% and 2.1%, respectively. The rate of upgrading was significantly associated with the presence of GP4 >16% versus ≤16% (OR 4.4, 95% CI 1.4-12.0; P=0.021) and with the presence of cribriform sub-type at biopsy specimens (OR 6.2, 95% CI 2.2-18.7; P<0.001).

CONCLUSIONS

We demonstrated that TBx technique significantly reduced the risk of GS 3+4 upgrading at RP, compared to SBx one. The rate of upgrading was significantly associated with GP4>16%, mostly when cribriform sub-type was present at biopsy specimens.

Targeted biopsy: benefits and limitations

PURPOSE OF REVIEW

To review the current literature regarding the role of multiparametric MRI and fusion-guided biopsies in urologic practice.

RECENT FINDINGS

Fusion biopsies consistently show an increase in the detection of clinically significant cancers and decrease in low-risk disease that may be more suitable for active surveillance. Although, when to incorporate multiparametric MRI into workup is not clearly agreed upon, studies have shown a clear benefit in both biopsy naïve and those with prior negative biopsies in determining the appropriate treatment strategy. More recently, cost-analysis models have been published that show that upfront MRIs are more cost-effective when considering missed cancers and treatment courses.

SUMMARY

With improved accuracy over systematic biopsies, fusion biopsies are a superior method for detection of the true grade of cancer for both biopsy naïve and patients with prior negative biopsies, choosing appropriate candidates for active surveillance, and monitoring progression on active surveillance.

PI-RADS Steering Committee: The PI-RADS Multiparametric MRI and MRI-directed Biopsy Pathway

High-quality evidence shows that MRI in biopsy-naive men can reduce the number of men who need prostate biopsy and can reduce the number of diagnoses of clinically insignificant cancers that are unlikely to cause harm. In men with prior negative biopsy results who remain under persistent suspicion, MRI improves the detection and localization of life-threatening prostate cancer with greater clinical utility than the current standard of care, systematic transrectal US-guided biopsy. Systematic analyses show that MRI-directed biopsy increases the effectiveness of the prostate cancer diagnosis pathway. The incorporation of MRI-directed pathways into clinical care guidelines in prostate cancer detection has begun. The widespread adoption of the Prostate Imaging Reporting and Data System (PI-RADS) for multiparametric MRI data acquisition, interpretation, and reporting has promoted these changes in practice. The PI-RADS MRI-directed biopsy pathway enables the delivery of key diagnostic benefits to men suspected of having cancer based on clinical suspicion. Herein, the PI-RADS Steering Committee discusses how the MRI pathway should be incorporated into routine clinical practice and the challenges in delivering the positive health impacts needed by men suspected of having clinically significant prostate cancer.

Spatial distribution of biopsy cores and the detection of intra-lesion pathologic heterogeneity

Objectives:

The objective of this study was to determine if spatial distribution of multiparametric magnetic resonance imaging–transrectal ultrasound (mpMRI-TRUS) fusion biopsy cores to the index lesion reveals trends in the detection of intra-lesion Gleason heterogeneity and a more optimal prostate biopsy strategy.

Methods:

Index lesion was the lesion with longest diameter on T2-weighted (T2W)-MRI. In cohort 1, fusion biopsy cores biopsies were taken in areas in the center of the target as well as 1 cm laterally on each side. For cohort 2, targeted biopsies were taken from the center of the lesion only. Heterogeneity was defined as difference in maximum Gleason score obtained from fusion cores in the center of the index lesion versus cores obtained from the periphery (cohort 1), or any difference in maximum Gleason score obtained from fusion cores targeted to the index lesion (cohort 2) compared with systematic 12 cores TRUS biopsy.

Results:

Ninety-nine consecutive patients (35 and 64 in cohorts 1 and 2, respectively) with median age (SD) and prostate-specific antigen (PSA) of 66.9 (±5.9) and 9.7 (±8.2) respectively, were included. Age, PSA, Prostate Imaging Reporting and Data System (PI-RADS) score, and preoperative MRI lesion size were not significantly different between cohorts. Gleason heterogeneity was observed at a significantly higher rate in cohort 1 versus cohort 2 (58% versus 24%; p = 0.041). In cohort 1, cores obtained from the center of the lesion had higher Gleason score than cores obtained from the periphery of the targeted lesion in 57% of cases.

Conclusions:

We demonstrate that there is observable tumor heterogeneity in biopsy specimens, and that increased number of cores, as well as cores focused on the center and periphery of the largest lesion in the prostate, provide more comprehensive diagnostic information about the patient’s clinical risk category than taking nonspecific cores targeted within the tumor.

Controversies in MR targeted biopsy: alone or combined, cognitive versus software-based fusion, transrectal versus transperineal approach?

PURPOSE

To review the evidence addressing current controversies around prostate biopsy. Specific questions explored were (1) mpMRI targeted (TgBx) alone versus combined with systematic (SBx) biopsy; (2) cognitive versus software-based targeted biopsy; (3) transrectal or transperineal route (TP).

METHODS

We performed a literature search of peer-reviewed English language articles using PubMed and the words "prostate" AND "biopsy". Web search was implemented by manual search.

RESULTS

Prostate mpMRI is revolutionizing prostate cancer (PCa) diagnosis, and TgBx improves the detection of clinically significant (cs) PCa compared to SBx alone. The utility of combining SBx-TgBx is variable, but in non-expert centres the two should be combined to overcome learning curve-limitations. Whether SBx should be maintained in expert centres depends on what rate of missed cancer the urological community and patients are prone to accept; this has implications for insignificant cancer diagnosis as well. TgBx may be more precise using a software-based-approach despite cognitive TgBx proved non-inferior in some studies, and may be used for large accessible lesions. TP-biopsies are feasible in an in-office setting. Avoidance of the rectum and accessibility of virtually all prostate areas are attractive features. However, this has to be balanced with local setting and resources implications. Ongoing trials will shed light on unsolved issues.

CONCLUSION

The prostate biopsy strategy should be tailored to local expertise, needs and resources availability. Targeted biopsy enhance the ratio between cs and insignificant cancer diagnosis, although some csPCa might be missed. Software-based TgBx are likely to be more precise, especially for new users, although the additional cost might be not justified in all cases. TPBx have ideal attributes for performing TgBx and avoiding infection, although this has resources implications.

The role of side-specific biopsy and dominant tumor location at radical prostatectomy in predicting the side of nodal metastases in organ confined prostate cancer: is lymphatic spread really unpredictable?

BACKGROUND

The aim of this study was to evaluate the correlation between the location of prostate cancer (PCa) either at biopsy or at radical prostatectomy (RP) specimens and the side of positive lymph nodes (LNs). Furthermore, we assessed the risk of contralateral LN metastasis (LNMs) in patients with unilateral positive biopsy and/or dominant lesion at RP.

METHODS

We reviewed retrospectively our prospectively maintained database of patients with LNM treated with robot-assisted RP and bilateral robot-assisted extended pelvic lymph node dissection (EPLND) for PCa from January 2014 to May 2018 at a surgical high-volume center. All men with a suspicion for PCa underwent a 12-cores prostate biopsy. In case of a first negative biopsy but the persistence of suspicion, all the patients underwent prostate multiparametric magnetic resonance imaging (mpMRI) and subsequently either fusion targeted biopsy (TBx) or systematic standard biopsy (SBx), in case of positive or negative mpMRI, respectively. All patients underwent a robot-assisted RP. Whole-mount histological sections resected from the RP specimens were used as reference standards.

RESULTS

Eighty-seven patients were enrolled for the study. Median number of LNs retrieved per patient was 26, specifically 13 and 12, on the left and right side, respectively. Seven of 24 (29.1%) right lobe positive biopsy showed positive LNs on the left side (one exclusively left, 6 bilateral LNMs). Again, 12 of 26 (46.1%) left lobe positive biopsy showed positive LNs on the right side (one exclusively right, 11 bilateral LNMs). No significant differences of performance to predict the side of LNMs were recorded in the SBx and TBx groups. Concerning RP specimens, only five of 22 (22.7%) right lobe dominant cases showed positive LNs on the left side (two exclusively left, 3 bilateral LN metastases). Again, none of 16 left lobe dominant cases showed positive LNs on the contralateral side (15 exclusively right, 1 bilateral LNMs).

CONCLUSIONS

Our results suggest confirmed that a unilateral LN dissection limited to the tumor-bearing side of the gland evaluated by biopsy specimens should not be recommended due to the substantial risk of missing contralateral LNMs.

Multiparametric Magnetic Resonance Imaging/Ultrasound Fusion Prostate Biopsy-Are 2 Biopsy Cores per Magnetic Resonance Imaging Lesion Required?

PURPOSE

For multiparametric magnetic resonance imaging/ultrasound fusion prostate biopsy the number of biopsy cores obtained is arbitrarily established by urologists. Moreover, a general consensus is lacking on the number of biopsy cores to be obtained from a single magnetic resonance imaging lesion. Therefore, we evaluated the feasibility of obtaining only 1 biopsy core per magnetic resonance imaging lesion.

MATERIALS AND METHODS

We retrospectively evaluated a total of 2,128 biopsy cores of 1,064 prostatic lesions (2 cores per lesion) in 418 patients in regard to prostate cancer detection (histology) and the Gleason score of the first biopsy core compared to the second biopsy core. Two analyses were performed, including patient level analysis based on prostate cancer detection per patient and lesion level analysis based exclusively on the histology of each lesion regardless of the overall histological outcome of the case.

RESULTS

The overall prostate cancer detection rate was 45.7% (191 of 418 patients). The first biopsy core detected 170 of all 191 prostate cancers (89%). In 17 of these 170 prostate cancers (10%) the second biopsy core revealed Gleason score upgrading. Nine of the 21 prostate cancers (43%) missed by the first biopsy core had a Gleason score of 6. Altogether 537 of the 2,128 biopsy cores were positive, including 283 first (26.6%) and 254 second (24%) biopsy cores (p ≤0.001). The concordance between the first and second biopsy cores was 89% (κ = 0.71). There was a discrepancy with Gleason score upgrading in 28 of 212 lesions (13.2%) with positive first and second biopsy cores.

CONCLUSIONS

Our study shows that obtaining more than 1 biopsy core per magnetic resonance imaging lesion only slightly improves the prostate cancer detection rate and Gleason grading.

Risk of Upgrading from Prostate Biopsy to Radical Prostatectomy Pathology-Does Saturation Biopsy of Index Lesion during Multiparametric Magnetic Resonance Imaging-Transrectal Ultrasound Fusion Biopsy Help?

PURPOSE

We sought to determine whether saturation of the index lesion during magnetic resonance imaging-transrectal ultrasound fusion guided biopsy would decrease the rate of pathological upgrading from biopsy to radical prostatectomy.

MATERIALS AND METHODS

We analyzed a prospectively maintained, single institution database for patients who underwent fusion and systematic biopsy followed by radical prostatectomy in 2010 to 2016. Index lesion was defined as the lesion with largest diameter on T2-weighted magnetic resonance imaging. In patients with a saturated index lesion transrectal fusion biopsy targets were obtained at 6 mm intervals along the long axis of the index lesion. In patients with a nonsaturated index lesion only 1 target was obtained from the lesion. Gleason 6, 7 and 8-10 were defined as low, intermediate and high risk, respectively.

RESULTS

Included in the study were 208 consecutive patients, including 86 with a saturated and 122 with a nonsaturated lesion. Median patient age was 62.0 years (IQR 10.0) and median prostate specific antigen was 7.1 ng/ml (IQR 8.0). The median number of biopsy cores per index lesion was higher in the saturated lesion group (4 vs 2, p <0.001). The risk category upgrade rate from systematic only, fusion only, and combined fusion and systematic biopsy results to prostatectomy was 40.9%, 23.6% and 13.8%, respectively. The risk category upgrade from combined fusion and systematic biopsy results was lower in the saturated than in the nonsaturated lesion group (7% vs 18%, p = 0.021). There was no difference in the upgrade rate based on systematic biopsy between the 2 groups. However, fusion biopsy results were significantly less upgraded in the saturated lesion group (Gleason upgrade 20.9% vs 36.9%, p = 0.014 and risk category upgrade 14% vs 30.3%, p = 0.006).

CONCLUSIONS

Our results demonstrate that saturation of the index lesion significantly decreases the risk of upgrading on radical prostatectomy by minimizing the impact of tumor heterogeneity.

MRI/US fusion-guided biopsy: performing exclusively targeted biopsies for the early detection of prostate cancer

PURPOSE

The aim of this study was to validate the role of MR/Ultrasound Fusion-Guided Targeted Biopsy as a first diagnostic modality in subjects with clinical suspicion of prostate cancer (PCa).

MATERIALS AND METHODS

108 men (age range 46-78 years) with clinical suspicion for PCa (PSA > 4 ng/mL) underwent multiparametric MRI of the prostate (mpMRI) and, when suspicious lesion were found (according to the PIRADSv2 scoring system), targeted biopsy was performed. All patients without significant alteration patterns at mpMRI have been referred for follow-up at 1 year.

RESULTS

91/108 patients showed on the mpMRI highly suspicious lesions (PIRADS 4 and 5); the remaining 17/108 patients revealed no significant alteration consistent with PCa (PIRADS 3). Among the first group of patients, 58/91 proved to be positive for PCa on the pathology report: 24 patients had a Gleason Score (GS) 6 (3 + 3); 18 patients GS 7 of which 7 (3 + 4) and 11 (4 + 3); 14 patients GS 8 (4 + 4); two patients GS 9 (5 + 4); 33 proved to be negative. Overall cancer detection rate (CDR) was 63%. However, the CDR rises significantly, up to 77%, after the 53 initial consecutive biopsies that were performed (p < 0,05) and thus identified as part of the learning curve. Patients of the second group (17/108) have been followed with serial PSA assessments, clinical reevaluation, and follow-up mpMRI.

CONCLUSION

Performing exclusively targeted MR/Ultrasound Fusion-Guided biopsies for the diagnosis of PCa in patients with suspicious PSA levels (> 4 ng/mL) increases the detection rate of clinically significant cancer, changing both the therapeutic options and the prognosis.