What Is the Negative Predictive Value of Multiparametric Magnetic Resonance Imaging in Excluding Prostate Cancer at Biopsy? A Systematic Review and Meta-analysis from the European Association of Urology Prostate Cancer Guidelines Panel

Combining prostate-specific antigen density with prostate imaging reporting and data system score version 2.1 to improve detection of clinically significant prostate cancer: A retrospective study

Globally, Prostate cancer (PCa) is the second most common cancer in the male population worldwide, but clinically significant prostate cancer (CSPCa) is more aggressive and causes to more deaths. The authors aimed to construct the risk category based on Prostate Imaging Reporting and Data System score version 2.1 (PI-RADS v2.1) in combination with Prostate-Specific Antigen Density (PSAD) to improve CSPCa detection and avoid unnecessary biopsy. Univariate and multivariate logistic regression and receiver-operating characteristic (ROC) curves were performed to compare the efficacy of the different predictors. The results revealed that PI-RADS v2.1 score and PSAD were independent predictors for CSPCa. Moreover, the combined factor shows a significantly higher predictive value than each single variable for the diagnosis of CSPCa. According to the risk stratification model constructed based on PI-RADS v2.1 score and PSAD, patients with PI-RADS v2.1 score of ≤2, or PI-RADS V2.1 score of 3 and PSA density of <0.15 ng/mL2, can avoid unnecessary of prostate biopsy and does not miss clinically significant prostate cancer.

Predicting Grade group 2 or higher cancer at prostate biopsy by 4Kscore in blood and uCaP microRNA model in urine

Elevated prostate-specific antigen (PSA) levels often lead to unnecessary and possibly harmful transrectal ultrasound guided biopsy, e.g. when the biopsy is negative or contains only low-grade insignificant cancer, unlikely to become symptomatic in the man's normal lifespan. A model based on four-kallikrein markers in blood (commercialized as 4Kscore) predicts risk of Grade group 2 or higher prostate cancer at biopsy, reducing unnecessary biopsies. We assessed whether these results extend to a single institution prostate biopsy cohort of Danish men and are enhanced by three microRNAs from urine (referred to as uCaP). The 4Kscore measured in cryopreserved blood from 234 men referred for 10+ core biopsy to Aarhus University Hospital, 29 with PSA > 25 ng/ml. We explored uCaP in urine from 157 of these men. Combined with age and DRE findings, both 4Kscore and uCaP could accurately predict Grade group 2 or higher prostate cancer (all patients: AUC = 0.802 and 0.797; PSA ≤ 25: AUC = 0.763 and 0.759). There was no additive effect when combining the 4Kscore and uCaP. Limitations include a study cohort with higher risk than commonly reported for biopsy cohorts. Our findings further support the clinical use of the 4Kscore to predict Grade group 2 or higher cancers in men being considered for biopsy.

Quantib Prostate Compared to an Expert Radiologist for the Diagnosis of Prostate Cancer on mpMRI: A Single-Center Preliminary Study

Background: To evaluate the clinical utility of an Artificial Intelligence (AI) radiology solution, Quantib Prostate, for prostate cancer (PCa) lesions detection on multiparametric Magnetic Resonance Images (mpMRI). Methods: Prostate mpMRI exams of 108 patients were retrospectively studied. The diagnostic performance of an expert radiologist (>8 years of experience) and of an inexperienced radiologist aided by Quantib software were compared. Three groups of patients were assessed: patients with positive mpMRI, positive target biopsy, and/or at least one positive random biopsy (group A, 73 patients); patients with positive mpMRI and a negative biopsy (group B, 14 patients), and patients with negative mpMRI who did not undergo biopsy (group-C, 21 patients). Results: In group A, the AI-assisted radiologist found new lesions with positive biopsy correlation, increasing the diagnostic PCa performance when compared with the expert radiologist, reaching an SE of 92.3% and a PPV of 90.1% (vs. 71.7% and 84.4%). In group A, the expert radiologist found 96 lesions on 73 mpMRI exams (17.7% PIRADS3, 56.3% PIRADS4, and 26% PIRADS5). The AI-assisted radiologist found 121 lesions (0.8% PIRADS3, 53.7% PIRADS4, and 45.5% PIRADS5). At biopsy, 33.9% of the lesions were ISUP1, 31.4% were ISUP2, 22% were ISUP3, 10.2% were ISUP4, and 2.5% were ISUP5. In group B, where biopsies were negative, the AI-assisted radiologist excluded three lesions but confirmed all the others. In group-C, the AI-assisted radiologist found 37 new lesions, most of them PIRADS 3, with 32.4% localized in the peripherical zone and 67.6% in the transition zone. Conclusions: Quantib software is a very sensitive tool to use specifically in high-risk patients (high PIRADS and high Gleason score).

Emerging MR methods for improved diagnosis of prostate cancer by multiparametric MRI

Current challenges of using serum prostate-specific antigen (PSA) level-based screening, such as the increased false positive rate, inability to detect clinically significant prostate cancer (PCa) with random biopsy, multifocality in PCa, and the molecular heterogeneity of PCa, can be addressed by integrating advanced multiparametric MR imaging (mpMRI) approaches into the diagnostic workup of PCa. The standard method for diagnosing PCa is a transrectal ultrasonography (TRUS)-guided systematic prostate biopsy, but it suffers from sampling errors and frequently fails to detect clinically significant PCa. mpMRI not only increases the detection of clinically significant PCa, but it also helps to reduce unnecessary biopsies because of its high negative predictive value. Furthermore, non-Cartesian image acquisition and compressed sensing have resulted in faster MR acquisition with improved signal-to-noise ratio, which can be used in quantitative MRI methods such as dynamic contrast-enhanced (DCE)-MRI. With the growing emphasis on the role of pre-biopsy mpMRI in the evaluation of PCa, there is an increased demand for innovative MRI methods that can improve PCa grading, detect clinically significant PCa, and biopsy guidance. To meet these demands, in addition to routine T1-weighted, T2-weighted, DCE-MRI, diffusion MRI, and MR spectroscopy, several new MR methods such as restriction spectrum imaging, vascular, extracellular, and restricted diffusion for cytometry in tumors (VERDICT) method, hybrid multi-dimensional MRI, luminal water imaging, and MR fingerprinting have been developed for a better characterization of the disease. Further, with the increasing interest in combining MR data with clinical and genomic data, there is a growing interest in utilizing radiomics and radiogenomics approaches. These big data can also be utilized in the development of computer-aided diagnostic tools, including automatic segmentation and the detection of clinically significant PCa using machine learning methods.

Automatic prostate and peri-prostatic fat segmentation based on pyramid mechanism fusion network for T2-weighted MRI

BACKGROUND AND OBJECTIVE

Automatic and accurate segmentation of prostate and peri-prostatic fat in male pelvic MRI images is a critical step in the diagnosis and prognosis of prostate cancer. The boundary of prostate tissue is not clear, which makes the task of automatic segmentation very challenging. The main issues, especially for the peri-prostatic fat, which is being offered for the first time, are hazy boundaries and a large form variation.

METHODS

We propose a pyramid mechanism fusion network (PMF-Net) to learn global features and more comprehensive context information. In the proposed PMF-Net, we devised two pyramid techniques in particular. A pyramid mechanism module made of dilated convolutions of varying rates is inserted before each down sample of the fundamental network architecture encoder. The module is intended to address the issue of information loss during the feature coding process, particularly in the case of segmentation object boundary information. In the transition stage from encoder to decoder, pyramid fusion module is designed to extract global features. The features of the decoder not only integrate the features of the previous stage after up sampling and the output features of pyramid mechanism, but also include the features of skipping connection transmission under the same scale of the encoder.

RESULTS

The segmentation results of prostate and peri-prostatic fat on numerous diverse male pelvic MRI datasets show that our proposed PMF-Net has higher performance than existing methods. The average surface distance (ASD) and Dice similarity coefficient (DSC) of prostate segmentation results reached 10.06 and 90.21%, respectively. The ASD and DSC of the peri-prostatic fat segmentation results reached 50.96 and 82.41%.

CONCLUSIONS

The results of our segmentation are substantially connected and consistent with those of expert manual segmentation. Furthermore, peri-prostatic fat segmentation is a new issue, and good automatic segmentation has substantial therapeutic implications.

Prostate cancer in PI-RADS scores 1 and 2 version 2.1: a comparison to previous PI-RADS versions

PURPOSE

To evaluate the validity of PI-RADS categories 1 and 2 version 2.1 (V2.1) as predictors of the absence of carcinoma and to reevaluate lesions that were analysed as suspicious prior to PI-RADS or according to PI-RADS versions 1 and 2 and classified as PI-RADS 1 or 2 in V2.1.

METHODS

Retrospective evaluation of 1170 multiparametric MRIs performed at one academic teaching hospital (2012-2019). Study cohort comprised 188 men that achieved PI-RADS scores 1 or 2 (V2.1) and underwent systematic and targeted biopsy, split into one group with suspect findings in the original reports that were created prior to PI-RADS or with version 1 and 2, and another group with unremarkable reports. Differences in presence of prostate cancer and PSA density were assessed by Chi-square and Fisher's exact test, and the negative predictive value (NPV) for both groups was conducted.

RESULTS

The NPV for clinically significant carcinoma (csCa) was 89.1% for 55 men with suspect findings in the original report and 93.2% for 133 men with negative MRI. There was no difference between the groups regarding the detection of csCa (p = 0.103). PSA density was significantly higher in the group with suspect original reports (p = 0.015).

CONCLUSION

A PI-RADS score 1 or 2 appears less likely to miss existing prostate cancer, although a small amount of csCa can be overlooked. In case of clinical suspicion or elevated PSA density and PI-RADS score 1 or 2, an individual decision has to be taken if biopsy is necessary or if monitoring is sufficient.

The benefit of adopting Microultrasound in the prostate cancer imaging pathway: A lesion-by-lesion analysis: Biopsies prostatiques guidée par micro-échographie, quel bénéfice ? Une analyse lésion par lésion

INTRODUCTION

- Microultrasound (MicroUS) is a novel imaging modality relying on a high-frequency transducer which confers a three-fold improvement in spatial resolution as compared with conventional transrectal ultrasound. We evaluated the diagnostic value of MRI-MicroUS fusion biopsy and determined the additional benefit of employing MicroUS.

METHODS

- Retrospective analysis of consecutive treatment-naïve men undergoing MRI-MicroUS fusion biopsy between May 2018 and March 2019. Pre-biopsy MRI was systematically reviewed in a dedicated meeting where suspicious lesions PIRADS ≥ 3 were registered and uploaded in the ExactVu MicroUS device. MRI and MicroUS lesions were individually marked in a PIRADS v2 scheme. The biopsy protocol included MRI-MicroUS fusion and MicroUS targeted biopsies; systematic biopsies were performed at clinician's discretion. The diagnostic value was evaluated in terms of detection rate of clinically significant prostate cancer, defined as Gleason pattern ≥ 4 at histology.

RESULTS

- In all, 148 patients with a median age of 69 years (IQR 63-74) and median PSA density of 0.16 ng/ml/cc (0.10-0.23) were included. Clinically significant cancer was detected in 42.5% (63/148) patients. MRI detected 89 lesions in the peripheral zone; 73% (65/89) were visible on MicroUS. Clinically significant cancer was detected in 46.1% (30/65) MRI and MicroUS visible lesions, and in 4.2% (1/24) lesions only visible on mpMRI. MicroUS additionally identified 35 suspicious lesions non-visible on MRI of which clinically significant cancer was present in 25.7% (9/35).

CONCLUSION

- Adding MicroUS to the conventional pathway seems to increase the detection rate of clinically significant disease in unselected men undergoing biopsy. © 2022 Elsevier Masson SAS. All rights reserved.

Comparison of Proclarix, PSA Density and MRI-ERSPC Risk Calculator to Select Patients for Prostate Biopsy after mpMRI

Tools to properly select candidates for prostate biopsy after magnetic resonance imaging (MRI) have usually been analyzed in overall populations with suspected prostate cancer (PCa). However, the performance of these tools can change regarding the Prostate Imaging-Reporting and Data System (PI-RADS) categories due to the different incidence of clinically significant PCa (csPCa). The objective of the study was to analyze PSA density (PSAD), MRI-ERSPC risk calculator (RC), and Proclarix to properly select candidates for prostate biopsy regarding PI-RADS categories. We performed a head-to-head analysis of 567 men with suspected PCa, PSA > 3 ng/mL and/or abnormal rectal examination, in whom two to four core transrectal ultrasound (TRUS) guided biopsies to PI-RADS ≥ three lesions and/or 12-core TRUS systematic biopsies were performed after 3-tesla mpMRI between January 2018 and March 2020 in one academic institution. The overall detection of csPCa was 40.9% (6% in PI-RADS < 3, 14.8% in PI-RADS 3, 55.3% in PI-RADS 4, and 88.9% in PI-RADS 5). MRI-ERSPC model exhibited a net benefit over PSAD and Proclarix in the overall population. Proclarix outperformed PSAD and MRI-ERSPC RC in PI-RADS ≤ 3. PSAD outperformed MRI-ESRPC RC and Proclarix in PI-RADS > 3, although none of them exhibited 100% sensitivity for csPCa in this setting. Therefore, tools to properly select candidates for prostate biopsy after MRI must be analyzed regarding the PI-RADS categories. While MRI-ERSPC RC outperformed PSAD and Proclarix in the overall population, Proclarix outperformed in PI-RADS ≤ 3, and no tool guaranteed 100% detection of csPCa in PI-RADS 4 and 5.

Comparative Analysis of PSA Density and an MRI-Based Predictive Model to Improve the Selection of Candidates for Prostate Biopsy

This study is a head-to-head comparison between mPSAD and MRI-PMbdex. The MRI-PMbdex was created from 2432 men with suspected PCa; this cohort comprised the development and external validation cohorts of the Barcelona MRI predictive model. Pre-biopsy 3-Tesla multiparametric MRI (mpMRI) and 2 to 4-core transrectal ultrasound (TRUS)-guided biopsies for suspicious lesions and/or 12-core TRUS systematic biopsies were scheduled. Clinically significant PCa (csPCa), defined as Gleason-based Grade Group 2 or higher, was detected in 934 men (38.4%). The area under the curve was 0.893 (95% confidence interval [CI]: 0.880−0.906) for MRI-PMbdex and 0.764 (95% CI: 0.774−0.783) for mPSAD, with p < 0.001. MRI-PMbdex showed net benefit over biopsy in all men when the probability of csPCa was greater than 2%, while mPSAD did the same when the probability of csPCa was greater than 18%. Thresholds of 13.5% for MRI-PMbdex and 0.628 ng/mL2 for mPSAD had 95% sensitivity for csPCa and presented 51.1% specificity for MRI-PMbdex and 19.6% specificity for mPSAD, with p < 0.001. MRI-PMbdex exhibited net benefit over mPSAD in men with prostate imaging report and data system (PI-RADS) <4, while neither exhibited any benefit in men with PI-RADS 5. Hence, we can conclude that MRI-PMbdex is more accurate than mPSAD for the proper selection of candidates for prostate biopsy among men with suspected PCa, with the exception of men with a PI-RAD S 5 score, for whom neither tool exhibited clinical guidance to determine the need for biopsy.

Paradigm Shift in Prostate Cancer Diagnosis: Pre-Biopsy Prostate Magnetic Resonance Imaging and Targeted Biopsy

With regard to the indolent clinical characteristics of prostate cancer (PCa), the more selective detection of clinically significant PCa (CSC) has been emphasized in its diagnosis and management. Magnetic resonance imaging (MRI) has advanced technically, and recent international cooperation has provided a standardized imaging and reporting system for prostate MRI. Accordingly, prostate MRI has recently been investigated and utilized as a triage tool before biopsy to guide tissue sampling to increase the detection rate of CSC beyond the staging tool for patients in whom PCa was already confirmed on conventional systematic biopsy. Radiologists must understand the current paradigm shift for better PCa diagnosis and management. This article reviewed the recent literature, demonstrating the diagnostic value of pre-biopsy prostate MRI with targeted biopsy and discussed unsolved issues regarding the paradigm shift in the diagnosis of PCa.

Early experience in avoiding biopsies for biopsy-naïve men with clinical suspicion of prostate cancer but non-suspicious biparametric magnetic resonance imaging results and prostate-specific antigen density < 0.15 ng/mL2: A 2-year follow-up study

Background

Only limited data have been published on the diagnostic accuracy of combining biparametric (bp) magnetic resonance imaging (MRI) and prostate-specific antigen density (PSAd) to rule out biopsies.

Purpose

The purpose is to assess the 2-year risk of being diagnosed with sPCa following the strategy of avoiding immediate biopsies in men with non-suspicious bp MRIs and a PSAd <0.15 ng/mL².

Material and Methods

Two hundred biopsy-naïve men with clinical suspicion of PCa underwent a pre-biopsy bp MRI from March to July 2019. Of these, 109 men had a Prostate Imaging Reporting and Data System (PI-RADS) score of 1–3 including 77 men with calculated PSAd <0.15 ng/mL². As a result, no biopsies were performed in these 77 men, who were clinically followed up for at least 2 years and re-examined in case of rising suspicion of sPCa. The remaining 32 men with a calculated PSAd ≥0.15 ng/mL² underwent systematic biopsies and targeted biopsies of any PI-RADS 3 lesion.

Results

One of the 77 men (1.3%) had an sPCa diagnosed within 2 years of follow-up. All men were referred back to their general practitioner within 1 year and 9% (7/77) were re-referred to the urology department during follow-up. Among these men, 43% (3/7) continued to have PSA levels that were above their individual thresholds at confirmatory testing and underwent secondary MRI scans.

Conclusions

No biopsies for men with bpMRI results exhibiting maximum PI-RADS 3 and with a PSAd <0.15 ng/mL² resulted in a 2-year risk of being diagnosed with sPCa of 1.3%.

Single center analysis of an advisable control interval for follow-up of patients with PI-RADS category 3 in multiparametric MRI of the prostate

To evaluate if follow-up mpMRI scans of patients in PI-RADS category 3 are safe enough to omit or delay prostate biopsy in the future and to determine an optimal control interval. This retrospective single center study includes consecutive PI-RADS category 3 patients with one or more follow-up mpMRI (T2WI, DWI, DCE) and subsequent MRI-targeted and systematic TRUS-guided biopsy between 2012 and 2018. Primary study objective was the verification of a significant PI-RADS category upgrade in follow-up mpMRI in patients with subsequent PCA positive biopsy versus patients with negative biopsy. Further objectives were development of the PI-RADS category and clinical parameters between initial and follow-up mpMRI in the context of histopathologic results and time interval. Eighty-nine patients (median PSA 6.6 ng/ml; PSAD 0.13 ng/ml/ml) were finally included (follow-up period 31 ± 18 months). 19 cases had PCA (median PSA 7.8 ng/ml; PSAD 0.14 ng/ml/ml). 4 cases had csPCA (median PSA 5.4 ng/ml; PSAD 0.13 ng/ml/ml) for which there was a significant PI-RADS upgrade after 12-24 months (mean 3.75; p = 0.01) compared to patients without PCA (mean 2.74). Without PCA the mean PI-RADS category decreased after 25-36 months (mean 2.74; p = 0.02). Clinical parameters did not change significantly except a PSAD increase for PCA patients after 24 months. Patients within PI-RADS category 3 may not need prompt biopsy since those with PCA reliably demonstrate a PI-RADS category upgrade in follow-up mpMRI after 12-24 months. PI-RADS 3 patients with negative biopsy do not benefit from follow-up mpMRI earlier than 24 months.

Can multi-parametric magnetic resonance imaging and prostate-specific antigen density accurately stratify patients prior to prostate biopsy?

Objective:

This study examines the diagnostic accuracy of multi-parametric magnetic resonance imaging (mpMRI) in a high-volume centre to potentially stratify patients prior to prostate biopsy.

Methods:

All biopsy naïve patients who had mpMRI prostate and transperineal biopsy of prostate (TPBx) in 2017 and 2018 were included. There were no exclusion criteria. All patients, regardless of the mpMRI result, underwent systematic template biopsy under general anaesthesia with cognitive target biopsy if indicated. Clinicopathological data were extracted from medical records. The primary outcome was the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of mpMRI prostate in the detection of prostate cancer (PCa) compared with template TPBx.

Results:

In total, 140 patients were included. Overall, 57.1% had a positive biopsy. A higher Prostate Imaging-Reporting and Data Systems (PI-RADS) score was associated with a higher risk of diagnosing clinically significant PCa (International Society of Urological Pathology (ISUP) ⩾ 2) ( p < 0.001). The sensitivity, specificity, NPV, and PPV of mpMRI in detecting clinically significant PCa with a PI-RADS ⩾ 3 lesion, was 95% (95% confidence interval (CI) 83.0–99.3%), 41% (95% CI 31.3–51.3%), 95.3% (95% CI 84.2–99.4%) and 39.2% (95% CI 29.4–49.6%), respectively. Combining this with prostate-specific antigen density (PSAD) of <0.15 further improved the NPV to 100% (86.3–100). Binomial logistic regression to understand the effects of PSA, DRE and PI-RADS score on predicting clinically significant PCa (ISUP ⩾ 2) found increasing PSA (odds ratio (OR) 1.06, (95% CI 1.00–1.11, p = 0.022)) and PI-RADS (OR 3.17, (95% CI 1.94–5.18, p < 0.001)) to be significant predictors. Malignant DRE was not a significant predictor ( p = 0.087).

Conclusion:

This study demonstrates that the high sensitivity and NPV of mpMRI combined with PSAD may play a pivotal role in stratifying men for prostate biopsy and help avoid biopsy and its associated morbidity in select patients.

Level of Evidence:

2b (Oxford Centre for Evidence-Based Medicine: Levels of Evidence)

Transrectal Ultrasound in Prostate Cancer: Current Utilization, Integration with mpMRI, HIFU and Other Emerging Applications

Transrectal ultrasound (TRUS) has been an invaluable tool in the assessment of prostate size, anatomy and aiding in prostate cancer (PCa) diagnosis for decades. Emerging techniques warrant an investigation into the efficacy of TRUS, how it compares to new techniques, and options to increase the accuracy of prostate cancer diagnosis. Currently, TRUS is used to guide both transrectal and transperineal biopsy approaches with similar cancer detection rates, but lower rates of infection have been reported with the transperineal approach, while lower rates of urinary retention are often reported with the transrectal approach. Multiparametric MRI has substantial benefits for prostate cancer diagnosis and triage such as lesion location, grading, and can be combined with TRUS to perform fusion biopsies targeting specific lesions. Micro-ultrasound generates higher resolution images that traditional ultrasound and has been shown effective at diagnosing PCa, giving it the potential to become a future standard of care. Finally, high-intensity focused ultrasound focal therapy administered via TRUS has been shown to offer safe and effective short-term oncological control for localized disease with low morbidity, and the precise nature makes it a viable option for salvage and repeat therapy.

WITHDRAWN: The benefit of adopting Microultrasound in the prostate cancer imaging pathway : A lesion-by-lesion analysis

INTRODUCTION

Microultrasound (MicroUS) is a novel imaging modality relying on a high-frequency transducer which confers a three-fold improvement in spatial resolution as compared with conventional transrectal ultrasound. We evaluated the diagnostic value of MRI-MicroUS fusion biopsy and determined the additional benefit of employing MicroUS.

METHODS

Retrospective analysis of consecutive treatment-naïve men undergoing MRI-MicroUS fusion biopsy between May 2018 and March 2019. Pre-biopsy MRI was systematically reviewed in a dedicated meeting where suspicious lesions PIRADS≥3 were registered and uploaded in the ExactVu MicroUS device. MRI and MicroUS lesions were individually marked in a PIRADS v2 scheme. The biopsy protocol included MRI-MicroUS fusion and MicroUS targeted biopsies; systematic biopsies were performed at clinician's discretion. The diagnostic value was evaluated in terms of detection rate of clinically significant prostate cancer, defined as Gleason pattern≥4 at histology.

RESULTS

In all, 148 patients with a median age of 69 years (IQR 63-74) and median PSA density of 0.16ng/ml/cc (0.10-0.23) were included. Clinically significant cancer was detected in 42.5% (63/148) patients. MRI detected 89 lesions in the peripheral zone; 73% (65/89) were visible on MicroUS. Clinically significant cancer was detected in 46.1% (30/65) MRI and MicroUS visible lesions, and in 4.2% (1/24) lesions only visible on mpMRI. MicroUS additionally identified 35 suspicious lesions non-visible on MRI of which clinically significant cancer was present in 25.7% (9/35).

CONCLUSION

Adding MicroUS to the conventional pathway seems to increase the detection rate of clinically significant disease in unselected men undergoing biopsy.

Balancing the benefits and harms of MRI-directed biopsy pathways

KEY POINTS

• Before a prostate biopsy, the likely benefits and the harms emanating from true and false test MRI results need to be balanced. Prioritizing patients' preferences and their tolerance to potential harms are essential to assess.• The decision curve analysis method is an analytical framework where the net clinical benefit is plotted against a range of risk thresholds of having important cancers, helping patients and their physicians to decide between cancer averse (important cancers being detected) and biopsy averse (biopsies avoided) strategies.• The decision curve analysis method showed that the incorporation of clinical risk factors with MRI findings optimizes biopsy outcomes over a range of clinically relevant risk thresholds, compared to other biopsy strategies.

Diagnostic Accuracy of Contemporary Selection Criteria in Prostate Cancer Patients Eligible for Active Surveillance: A Bayesian Network Meta-Analysis

Background

Several active surveillance (AS) criteria have been established to screen insignificant prostate cancer (insigPCa, defined as organ confined, low grade and small volume tumors confirmed by postoperative pathology). However, their comparative diagnostic performance varies. The aim of this study was to compare the diagnostic accuracy of contemporary AS criteria and validate the absolute diagnostic odds ratio (DOR) of optimal AS criteria.

Methods

First, we searched Pubmed and performed a Bayesian network meta-analysis (NMA) to compare the diagnostic accuracy of contemporary AS criteria and obtained a relative ranking. Then, we searched Pubmed again to perform another meta-analysis to validate the absolute DOR of the top-ranked AS criteria derived from the NMA with two endpoints: insigPCa and favorable disease (defined as organ confined, low grade tumors). Subgroup and meta-regression analyses were conducted to identify any potential heterogeneity in the results. Publication bias was evaluated.

Results

Seven eligible retrospective studies with 3,336 participants were identified for the NMA. The diagnostic accuracy of AS criteria ranked from best to worst, was as follows: Epstein Criteria (EC), Yonsei criteria, Prostate Cancer Research International: Active Surveillance (PRIAS), University of Miami (UM), University of California-San Francisco (UCSF), Memorial Sloan-Kettering Cancer Center (MSKCC), and University of Toronto (UT). I² = 50.5%, and sensitivity analysis with different insigPCa definitions supported the robustness of the results. In the subsequent meta-analysis of DOR of EC, insigPCa and favorable disease were identified as endpoints in ten and twenty-two studies, respectively. The pooled DOR for insigPCa and favorable disease were 0.44 (95%CI, 0.31–0.58) and 0.66 (95%CI, 0.61–0.71), respectively. According to a subgroup analysis, the DOR for favorable disease was significantly higher in US institutions than that in other regions. No significant heterogeneity or evidence of publication bias was identified.

Conclusions

Among the seven AS criteria evaluated in this study, EC was optimal for positively identifying insigPCa patients. The pooled diagnostic accuracy of EC was 0.44 for insigPCa and 0.66 when a more liberal endpoint, favorable disease, was used.

Systematic Review Registration

[https://www.crd.york.ac.uk/prospero/], PROSPERO [CRD42020157048].

Integrative Machine Learning Prediction of Prostate Biopsy Results From Negative Multiparametric MRI

BACKGROUND

Multiparametric MRI (mpMRI) is commonly recommended as a triage test prior to any prostate biopsy. However, there exists limited consensus on which patients with a negative prostate mpMRI could avoid prostate biopsy.

PURPOSE

To identify which patient could safely avoid prostate biopsy when the prostate mpMRI is negative, via a radiomics-based machine learning approach.

STUDY TYPE

Retrospective.

SUBJECTS

Three hundred thirty patients with negative prostate 3T mpMRI between January 2016 and December 2018 were included.

FIELD STRENGTH/SEQUENCE

A 3.0 T/T2-weighted turbo spin echo (TSE) imaging (T₂ WI) and diffusion-weighted imaging (DWI).

ASSESSMENT

The integrative machine learning (iML) model was trained to predict negative prostate biopsy results, utilizing both radiomics and clinical features. The final study cohort comprised 330 consecutive patients with negative mpMRI (PI-RADS < 3) who underwent systematic transrectal ultrasound-guided (TRUS) or MR-ultrasound fusion (MRUS) biopsy within 6 months. A secondary analysis of biopsy naïve subcohort (n = 227) was also conducted.

STATISTICAL TESTS

The Mann-Whitney U test and Chi-Squared test were utilized to evaluate the significance of difference of clinical features between prostate biopsy positive and negative groups. The model performance was validated using leave-one-out cross-validation (LOOCV) and measured by AUC, sensitivity, specificity, and negative predictive value (NPV).

RESULTS

Overall, 306/330 (NPV 92.7%) of the final study cohort patients had negative biopsies, and 207/227 (NPV 91.2%) of the biopsy naïve subcohort patients had negative biopsies. Our iML model achieved NPVs of 98.3% and 98.0% for the study cohort and subcohort, respectively, superior to prostate-specific antigen density (PSAD)-based risk assessment with NPVs of 94.9% and 93.9%, respectively.

DATA CONCLUSION

The proposed iML model achieved high performance in predicting negative prostate biopsy results for patients with negative mpMRI. With improved NPVs, the proposed model can be used to stratify patients who in whom we might obviate biopsies, thus reducing the number of unnecessary biopsies.

EVIDENCE LEVEL

3 TECHNICAL EFFICACY: Stage 2.

The utility of prostate MRI within active surveillance: description of the evidence

Purpose

We present an overview of the literature regarding the use of MRI in active surveillance of prostate cancer.

Methods

Both MEDLINE^® and Cochrane Library were queried up to May 2020 for studies of men on active surveillance with MRI and later confirmatory biopsy. The terms studied were ‘prostate cancer’ as the anchor followed by two of the following: active surveillance, surveillance, active monitoring, MRI, NMR, magnetic resonance imaging,  MRI, and multiparametric MRI. Studies were excluded if pathologic reclassification (GG1 →  ≥ GG2) and PI-RADS or equivalent was not reported.

Results

Within active surveillance, baseline MRI is effective for identifying clinically significant prostate cancer and thus associated with fewer reclassification events. A positive initial MRI (≥ PI-RADS 3) with GG1 identified at biopsy has a positive predictive value (PPV) of 35–40% for reclassification by 3 years. MRI possessed a stronger negative predictive value, with a negative MRI (≤ PI-RADS 2) yielding a negative predictive value of up to 85% at 3 years. Surveillance MRI, obtained after initial biopsy, yielded a PPV of 11–65% and NPV of 85–95% for reclassification.

Conclusion

MRI is useful for initial risk stratification of prostate cancer in men on active surveillance, especially if MRI is negative when imaging is obtained during surveillance. While useful, MRI cannot replace biopsy and further research is necessary to fully integrate MRI into active surveillance.

Characteristics of α2,3-sialyl N-glycosylated PSA as a biomarker for clinically significant prostate cancer in men with elevated PSA level

BACKGROUND

The presence of glycosylated isoforms of prostate-specific antigen (PSA) in prostate cancer (PC) cells is a potential marker of their aggressiveness. We characterized the origin of α2,3-sialylated prostate-specific antigen (S23PSA) by tissue-based sialylation-related gene expression and studied the performance of S23PSA density (S23PSAD) alone and in combination with multiparametric magnetic resonance imaging (MRI) for the detection of clinically significant prostate cancer in men with elevated PSA.

METHODS

Tissue-based quantification of S23PSA and sialyltransferase and sialidase gene expression was evaluated in 71 radical prostatectomy specimens. The diagnostic performance of S23PSAD was studied in 1099 men retrospectively enrolled in a multicenter systematic biopsy (SBx) cohort. We correlated the S23PSAD with Prostate Imaging Reporting and Data System (PI-RADS) scores in 98 men prospectively enrolled in a single-center MRI-targeted biopsy (MRI-TBx) cohort. The primary outcome was the PC-diagnostic performance of the S23PSAD, the secondary outcome was the avoidable biopsy rate of S23PSAD combined with DRE and total PSA (tPSA), and with or without PI-RADS.

RESULTS

S23PSA was significantly higher in Gleason pattern 4 and 5 compared with benign prostate tissue. In the retrospective cohort, the performance of S23PSAD for detecting PC was superior to tPSA or PSA density (PSAD) (AUC: 0.7758 vs. 0.6360 and 0.7509, respectively). In the prospective cohort, S23PSAD was superior to tPSA, PSAD, and PI-RADS (AUC: 0.7725 vs. 0.5901, 0.7439 and 0.7305, respectively), and S23PSAD + PI-RADS + DRE + tPSA was superior to DRE + tPSA+PI-RADS with avoidance rate of MRI-TBx (13% vs. 1%) at 30% risk threshold.

CONCLUSIONS

The diagnostic performance of S23PSAD was superior to conventional strategies but comparable to mpMRI.

Results from a PI-RADS-based MRI-directed diagnostic pathway for biopsy-naive patients in a non-university hospital

Purpose

To assess the safety and performance of a MRI-directed diagnostic pathway for patients with first-time suspicion of prostate cancer in a non-university hospital.

Methods

Between May 2017 and December 2018 all biopsy-naive patients examined in our hospital followed a MRI-directed diagnostic work-up algorithm based on PI-RADS score. In short, PI-RADS 1–2 was generally not biopsied and PI-RADS 3–5 was reviewed by a multidisciplinary team. Patients with PI-RADS 4-5 were all referred to biopsy, either transrectal ultrasound-guided biopsy or MRI in-bore biopsy for small tumors and for sites difficult to access. PI-RADS scores were compared to the histopathology from biopsies and surgical specimens for patients who had prostatectomy. Non-biopsied patients were referred to a safety net monitoring regimen.

Results

Two hundred and ninety-eight men were enrolled. 97 (33%) had PI-RADS 1–2, 44 (15%) had PI-RADS 3, and 157 (53%) had PI-RADS 4–5. 116 (39%) of the patients avoided biopsy. None of these were diagnosed with significant cancer within 2–3.5 years of safety net monitoring. Almost all high ISUP grade groups (≥ 3) were in the PI-RADS 4–5 category (98%). Prostatectomy specimens and systematic biopsies from MRI-negative areas indicated that very few clinically significant cancers were missed by the MRI-directed diagnostic pathway.

Conclusion

Our findings add to evidence that a MRI-directed diagnostic pathway can be safely established in a non-university hospital. The pathway reduced the number of biopsies and reliably detected the site of the most aggressive cancers.

Graphic abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s00261-021-03249-8.

Clinically Significant Prostate Cancer Detection After A Negative Prebiopsy MRI Examination: Comparison of Biparametric Versus Multiparametric MRI

Background: The frequency of clinically significant prostate cancer (csPCa) following negative biparametric MRI (bpMRI) and multiparametric MRI (mpMRI) has not been well investigated in direct comparative studies. Objective: To compare the frequency of csPCa after negative prebiopsy bpMRI and mpMRI, and to evaluate factors that predict csPca in the two cohorts. Methods: This retrospective study included 232 men (mean age, 64.5 years) with negative bpMRI from August 2017 to March 2020 and193 men (mean age, 69.0 years) with negative mpMRI from January 2018 to December 2018, defining PI-RADS category of 1 or 2 as negative. Our institution offers bpMRI as a low-cost self-pay option for patients without insurer coverage of prebiospy mpMRI. Patient characteristics and subsequent biopsy results were recorded. csPCa was defined as Gleason score ≥3+4. Multivariable regression analyses were performed to identify independent predictors of csPCa. AUC of prostate specific antigen density (PSAD) for csPCA was computed, and diagnostic performance of PSAD was assessed at a clinically established threshold of 0.15 ng/mL2. Results: Systematic biopsy was performed after negative bpMRI in 41.4% (96/232), versus after negative mpMRI in 30.5% (59/193) (p=.02). Among those undergoing biopsy, csPCa was present in 15.6% (15/96) in the mpMRI cohort versus 13.6% (8/59) in the bpMRI cohort (p=.69). NPV for csPCa was 84% (81/96) for bpMRI and 86% (51/59) for mpMRI. In multivariable analyses, independent predictors of csPCa included smaller prostate volume (OR=0.27, p<.001) and greater PSAD (OR=3.09, p<.001). In multivariable models, bpMRI (compared with mpMRI) did not independently predict csPCa (p>.05). PSAD had AUC for csPCa of 0.77 (95% CI: 0.64, 0.89) in the bpMRI cohort versus 0.68 (95% CI: 0.42, 0.93) in the mpMRI cohort. For detecting csPCa, PSAD threshold of 0.15 ng/mL2 had NPV of 90% and PPV of 28%, in the bpMRI cohort, versus NPV of 92% and PPV of 44%in the mpMRI cohort. Conclusion: The frequency of csPCa was not significantly different on systematic biopsy performed after negative bpMRI and mpMRI examinations. PSAD had similar diagnostic utility for csPca in both cohorts. Clinical Impact: Either bpMRI or mpMRI, in combination with PSAD, can help avoid negative prostate biopsies.

Analysis of the usefulness of magnetic resonance imaging and clinical parameters in the detection of prostate cancer in the first systematic biopsy combined with targeted cognitive biopsy

Introduction

The study aimed to assess the suitability of multiparametric magnetic resonance prostate imaging (mpMRI) in combination with clinical parameters [prostate-specific antigen (PSA), digital rectal examination (DRE)] in the identification of men at risk of the presence of prostate cancer (PCa) and clinically significant prostate cancer (csPCa, Gleason Score ≥3+4) in the cognitive fusion with systematic prostate biopsy.

Material and methods

We retrospectively evaluated a population of 215 biopsy – naive patients with a clinical suspicion of prostate cancer. The results of mpMRI, DRE, PSA and biopsy were analyzed. MpMRI of the prostate according to the Prostate Imaging Reporting and Data System (PI-RADS) v.2.0 scheme preceded cognitive fusion and systematic transrectal prostate biopsy. Uni- and multivariable logistic regression analysis (MVA) was used to identify the variables determining the risk of detecting PCa overall and csPCa.

Results

In MVA, it was established that the combination of variables such as PSA level [odds ratio (OR) 1.195; p = 0.002], PI-RADS ≥3 (OR 7.7; p = 0.002), prostate volume (OR 0.98; p = 0.017) significantly determines the probability of PCa detection in biopsy, while for csPCa it is PSA level (OR 1.14; p = 0.004), DRE (+) (OR 5.75; p <0.001), PI-RADS ≥4 (OR 6.5; p <0.001). Analysis of mpMRI diagnostic value for PI-RADS ≥4 revealed better sensitivity (88.9% vs 82.6%) and better negative predictive value (NPV) (94.5% vs 82.4%) for detection of csPCa than for PCa overall.

Conclusions

MpMRI results combining with DRE and PSA parameters help to identify men at high – or low risk of csPCa detection in the first – time biopsy.

Repeat MRI during active surveillance: natural history of prostatic lesions and upgrading rates

OBJECTIVES

To assess upgrading rates in patients on active surveillance (AS) for prostate cancer (PCa) after serial multiparametric magnetic resonance imaging (mpMRI).

METHODS

We conducted a retrospective analysis of 558 patients. Five different criteria for mpMRI progression were used: 1) a Prostate Imaging Reporting and Data System (PI-RADS) score increase; 2) a lesion size increase; 3) an extraprostatic extension score increase; 4) overall mpMRI progression; and 5) the number of criteria met for mpMRI progression (0 vs 1 vs 2-3). In addition, two definitions of PCa upgrading were evaluated: 1) International Society of Urological Pathology Grade Group (ISUP GG) ≥2 with >10% of pattern 4 and 2) ISUP GG ≥ 3. Estimated annual percent changes methodology was used to show the temporal trends of mpMRI progression criteria. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of mpMRI progression criteria were also analysed. Multivariable logistic regression models tested PCa upgrading rates.

RESULTS

Lower rates over time for all mpMRI progression criteria were observed. The NPV of serial mpMRI scans ranged from 90.5% to 93.5% (ISUP GG≥2 with >10% of pattern 4 PCa upgrading) and from 98% to 99% (ISUP GG≥3 PCa upgrading), depending on the criteria used for mpMRI progression. A prostate-specific antigen density (PSAD) threshold of 0.15 ng/mL/mL was used to substratify those patients who would be able to skip a prostate biopsy. In multivariable logistic regression models assessing PCa upgrading rates, all five mpMRI progression criteria achieved independent predictor status.

CONCLUSION

During AS, approximately 27% of patients experience mpMRI progression at first repeat MRI. However, the rates of mpMRI progression decrease over time at subsequent mpMRI scans. Patients with stable mpMRI findings and with PSAD < 0.15 ng/mL/mL could safely skip surveillance biopsies. Conversely, patients who experience mpMRI progression should undergo a prostate biopsy.

Rationale and protocol for randomized study of transrectal and transperineal prostate biopsy efficacy and complications (ProBE-PC study)

BACKGROUND

Rrisk of infection and hospitalization after transrectal prostate biopsy (TRBx) has been increasing worldwide. Several modified antibiotic regimens have met with variable success in preventing such infections. Transperineal prostate biopsy (TPBx) is increasingly recommended as the preferred alternative due to a potentially lower risk of post-biopsy infections. Aim of this review is to define the magnitude of post-biopsy complications and the effectiveness of preventive strategies, including TPBx approach.

METHODS

We performed a focused review of literature on infectious complications after TRBx and detailed the use of various preventive measures. We summarized the effectiveness of several preventive measures, including TPBx, and outlined the inconsistencies in reported outcomes. We identified potential barriers to the uptake of TPBx, including the gap in knowledge such as lack of high-quality evidence.

RESULTS

Several antibiotic prophylaxis protocols, including targeted and augmented, have been utilized for TRBx without demonstrating a clearly superior regimen. Of the non-antibiotic preventive measure, povidone-iodine rectal prep appears to be most effective strategy. Several single-arm cohort studies have reported very low rates of infections after TPBx and demonstrated the feasibility of an office-based procedure. However, barriers to the adoption of TPBx exist including retrospective data, and conflicting results showing minimal reduction in complications with increased burden of resource utilization. Presently, there are no randomized studies comparing the infectious complications after TRBx and TPBx. We discuss the rationale and protocol for a randomized controlled trial to determine the comparative effectiveness of biopsy techniques.

CONCLUSIONS

TPBx approach has the potential to lower the rate of post-biopsy infections and hospitalizations. However, there are several barriers to widespread adoption of this approach including inconsistencies in reported outcomes and lack of Level-1 evidence. Randomized controlled studies are required to directly compare the infectious complications associated with each biopsy procedure.

Emerging role of multiparametric magnetic resonance imaging in identifying clinically relevant localized prostate cancer

PURPOSE OF REVIEW

To explore the recent advances and utility of multiparametric magnetic resonance imaging (mpMRI) in the diagnosis and risk-stratification of prostate cancer.

RECENT FINDINGS

Low-risk, clinically insignificant prostate cancer has a decreased risk of morbidity or mortality. Meanwhile, patients with intermediate and high-risk prostate cancer may significantly benefit from interventions like radiation or surgery. To appropriately risk stratify these patients, MRI has emerged as the imaging modality in the last decade to assist in defining prostate cancer significance, location, and biologic aggressiveness. Traditional 12-core transrectal ultrasound-guided biopsy is associated with over-detection, and ultimately over-treatment of clinically insignificant disease, and the under-detection of clinically significant disease. Biopsy accuracy is improved with MRI-guided targeted biopsy and with the use of standardized risk stratification imaging score systems. Cancer detection accuracy is further improved with combined biopsy techniques that include both systematic and MRI-targeted biopsy that aid in detection of MRI-invisible lesions.

SUMMARY

mpMRI is an area of expanding innovation that continues to refine the diagnostic accuracy of prostate biopsies. As mpMRI-targeted biopsy in prostate cancer becomes more commonplace, advances like artificial intelligence and less invasive dynamic metabolic imaging will continue to improve the utility of MRI.

Prostate cancer: Molecular imaging and MRI

The role of molecular imaging in initial evaluation of men with presumed or established diagnosis of prostate cancer and work up of biochemical recurrence and metastatic disease is rapidly evolving due to superior diagnostic performance compared to anatomic imaging. However, variable tumor biology and expression of transmembrane proteins or metabolic alterations poses a challenge. We review the evidence and controversies with emphasis on emerging PET radiopharmaceuticals and experience on clinical utility of PET/CT and PET/MRI in diagnosis and management of prostate cancer.

A European Model for an Organised Risk-stratified Early Detection Programme for Prostate Cancer

CONTEXT

Overdiagnosis as the argument to stop prostate cancer (PCa) screening is less valid since the introduction of new technologies such as risk calculators (RCs) and magnetic resonance imaging (MRI). These new technologies result in fewer unnecessary biopsy procedures and fewer cases of both overdiagnosis and underdetection. Therefore, we can now adequately respond to the growing and urgent need for a structured risk assessment to detect PCa early.

OBJECTIVE

To provide expert discussion on the existing evidence for a previously published risk-stratified strategy regarding an organised population-based early detection programme for PCa.

EVIDENCE ACQUISITION

The proposed algorithm for early detection of PCa emerged from expert consensus by the authors based on available evidence derived from a nonsystematic review of the current literature using Medline/PubMed, Cochrane Library database, ClinicalTrials.gov, ISRCTN Registry, and the European Association of Urology guidelines on PCa.

EVIDENCE SYNTHESIS

Although not confirmed by the highest level of evidence, current literature and guidelines point towards an algorithm for early detection of PCa that starts with risk-based prostate-specific antigen (PSA) testing, followed by multivariable risk stratification with RCs. All men who are classified to be at intermediate and high risk are then offered prostate MRI. The combined data from RCs and MRI results can be used to select men for prostate biopsy. Low-risk men return to a risk-based safety net that includes individualised PSA-interval tests and, if necessary, repeated MRI. Depending on local availability, the use of the different risk stratification tools may be adapted.

CONCLUSIONS

We present a risk-stratified algorithm for an organised population-based early detection programme for clinically significant PCa. Although the proposed strategy has not yet been analysed prospectively, it exploits and may even improve the most important available benefits of "PSA-only" screening studies, while at the same time reduces unnecessary biopsies and overdiagnosis by using new risk stratification tools.

PATIENT SUMMARY

This paper presents a personalised strategy that enables selective early detection of prostate cancer by combining prostate-specific antigen (interval) testing' prediction models (risk calculators), and magnetic resonance imaging scans. This will likely lead to reduced prostate cancer-related morbidity and mortality, while reducing the need for prostate biopsy and limiting overdiagnosis.

Clinical characteristics and oncological outcomes in negative multiparametric MRI patients undergoing robot-assisted radical prostatectomy

BACKGROUND

Efforts are ongoing to try and find ways to reduce the number of unnecessary prostate biopsies without missing clinically significant prostate cancers (csPCa). The utility of multiparametric magnetic resonance imaging (mpMRI) in detecting prostate cancer (PCa) shows promise to be used as triage test for systematic prostate biopsy. Our aim is to Study clinical parameters and oncological outcomes in men with negative mpMRI (nMRI; PI-RADS v2 scores of ≤ 2) who underwent robot-assisted radical prostatectomy (RARP) to evaluate nMRI's practicality as a biopsy triage test.

METHODS

Retrospective analysis of 331 men with nMRI who underwent RARP between 2014 and 2020 compared with men with positive mpMRI (pMRI; PI-RADS v2 scores ≥ 3, N = 1770). csPCa was defined as Gleason score ≥ 3 + 4 and biochemical recurrence (BCR) was defined as PSA > 0.2 ng/ml on two occasions. Biopsies were graded with the International Society of Urologic Pathology [ISUP] grade. Descriptive statistics for nMRI and pMRI were performed. Mann-Whitney U test was used for continuous variables and χ ² for categorical variables. Univariable and multivariable regression analyses were performed.

RESULTS

Univariable analysis shows statistically significant difference (p < .05) between median age (nMRI-61 years vs. pMRI 63 years), race (higher incidence of nMRI in African American men), use of 5-alpha reductase inhibitors (higher rate in nMRI). While incidence rates of family history of PCa, suspicious digital rectal examination (DRE) findings, median PSA levels and 4Kscore, were lower in nMRI versus pMRI. Rates of positive surgical margins and BCR were comparable in nMRI versus pMRI. Biopsy ISUP Grades I and II upgraded by 51% and 12%, respectively in final pathology. African American race and no history of the prior negative biopsy were significant predictors for upgrading.

CONCLUSION

Men with nMRI pose diagnostic challenges as they tend to be younger patients with lower rates of suspicious DRE findings and lower 4K scores, yet comparable oncological outcomes in csPCa rates, positive surgical margins, and BCR rates.

A 25-year perspective on evaluation and understanding of biomarkers in urologic cancers

The past 25 years have witnessed an explosion of investigative attempts to identify clinically useful biomarkers which can have meaningful impacts for patients with urologic cancers. However, in spite of the enormous amount of research aiming to identify markers with the hope of impacting patient care, only a handful have proven to have true clinical utility. Improvements in targeted imaging, pan-omics evaluation, and genetic sequencing at the tissue and single-cell levels have yielded many potential targets for continued biomarker investigation. This article, as one in this series for the 25th Anniversary Issue of Urologic Oncology: Seminars and Original Investigations, serves to give a perspective on our progress and failures over the past quarter-century in our highest volume urologic cancers: prostate, bladder, and kidney cancers.

Does PSA level affect the choice of prostate puncture methods among MRI-ultrasound fusion targeted biopsy, transrectal ultrasound systematic biopsy or the combination of both?

OBJECTIVES

To explore whether prostate-specific antigen (PSA) affects the choice of prostate puncture methods by comparing MRI-ultrasound fusion targeted biopsy (MRI-TBx) with transrectal ultrasound systematic biopsy (TRUS-SBx) in the detection of prostate cancer (PCa), clinically significant prostate cancer (csPCa) and non-clinically significant prostate cancer (nsPCa) in different PSA groups (<10.0,10.0-20.0 and>20.0 ng ml-1).

METHODS

A total of 190 patients with 215 lesions who underwent both MRI-TBx and TRUS-SBx were included in this retrospective study. PSA was measured pre-operatively and stratified to three levels. The detection rates of PCa, csPCa and nsPCa through different methods (MRI-TBx, TRUS-SBx, or MRI-TBx +TRUS SBx) were compared with stratification by PSA.

RESULTS

Among the 190 patients, the histopathological results revealed PCa in 126 cases, including 119 csPCa. In PSA <10.0 ng ml-1 group, although the detection rates of PCa and csPCa by MRI-TBx were higher than those of TRUS-SBx, no significant differences were observed (p = 0.741; p = 0.400). In PSA 10.0-20.0 ng ml-1 group, difference between the detection rate of csPCa with TRUS-SBx and the combined method was statistically significant (p = 0.044). As for PSA >20.0 ng ml-1, MRI-TBx had a higher csPCa rate than TRUS-SBx with no statistical significance noted (p = 0.600).

CONCLUSION

MRI-TBx combined with TRUS-SBx could be suitable as a standard detection approach for csPCa in patients with PSA 10.0-20.0 ng ml-1. As for PSA >20.0 and <10.0 ng ml-1, both MRI-TBx and TRUS-SBx might provide effective solutions for tumor detection.

ADVANCES IN KNOWLEDGE

This study gives an account of choosing appropriate prostate puncture methods through PSA level.

Usability and diagnostic accuracy of different MRI/ultrasound-guided fusion biopsy systems for the detection of clinically significant and insignificant prostate cancer: a prospective cohort study

PURPOSE

To explore the usability and diagnostic accuracy for prostate cancer of three multiparametric magnetic resonance imaging (mpMRI)/transrectal ultrasound (TRUS)-guided fusion biopsy systems operated by the same urologists.

METHODS

We performed a prospective, observational study including patients that underwent prostate biopsy due to a visible lesion in mpMRI (PI-RADS ≥ 3). We consecutively assessed two platforms with a rigid image registration (BioJet, D&K Technologies and UroNav, Invivo Corporation) and one with an elastic registration (Trinity, KOELIS). Four urologists evaluated each fusion system in terms of usability based on the System Usability Scale and diagnostic accuracy based on the detection of prostate cancer.

RESULTS

We enrolled 60 consecutive patients that received mpMRI/TRUS-guided prostate biopsy with the BioJet (n = 20), UroNav (n = 20) or Trinity (n = 20) fusion system. Comparing the rigid with the elastic registration systems, the rigid registration systems were more user-friendly compared to the elastic registration systems (p = 0.012). Similarly, the prostate biopsy with the rigid registration systems had a shorter duration compared to the elastic registration system (p < 0.001). Overall, 40 cases of prostate cancer were detected. Of them, both the BioJet and UroNav fusion systems detected 13 prostate cancer cases, while the Trinity detected 14. No significant differences were demonstrated among the three fusion biopsy systems in terms of highest ISUP Grade Group (p > 0.99).

CONCLUSIONS

Rigid fusion biopsy systems are easier to use and provide shorter operative time compared to elastic systems, while both types of platforms display similar detection rates for prostate cancer. Still, further high-quality, long-term results are mandatory.

Reliability of Serial Prostate Magnetic Resonance Imaging to Detect Prostate Cancer Progression During Active Surveillance: A Systematic Review and Meta-analysis

CONTEXT

Although magnetic resonance imaging (MRI) is broadly implemented into active surveillance (AS) protocols, data on the reliability of serial MRI in order to help guide follow-up biopsy are inconclusive.

OBJECTIVE

To assess the diagnostic estimates of serial prostate MRI for prostate cancer (PCa) progression during AS.

EVIDENCE ACQUISITION

We systematically searched PubMed, Scopus, and Web of Science databases to select studies analyzing the association between changes on serial prostate MRI and PCa progression during AS. We included studies that provided data for MRI progression, which allowed us to calculate diagnostic estimates. We compared Prostate Cancer Radiological Estimation of Change in Sequential Evaluation (PRECISE) accuracy with institution-specific definitions.

EVIDENCE SYNTHESIS

We included 15 studies with 2240 patients. Six used PRECISE criteria and nine institution-specific definitions of MRI progression. The pooled PCa progression rate, which included histological progression to Gleason grade ≥2, was 27%. The pooled sensitivity and specificity were 0.59 (95% confidence interval [CI] 0.44-0.73) and 0.75 (95% CI 0.66-0.84) respectively. There was significant heterogeneity between included studies. Depending on PCa progression prevalence, the pooled negative predictive value for serial prostate MRI ranged from 0.81 (95% CI 0.73-0.88) to 0.88 (95% CI 0.83-0.93) and the pooled positive predictive value ranged from 0.37 (95% CI 0.24-0.54) to 0.50 (95% CI 0.36-0.66). There were no significant differences in the pooled sensitivity (p = 0.37) and specificity (p = 0.74) of PRECISE and institution-specific schemes.

CONCLUSIONS

Serial MRI still should not be considered a sole factor for excluding PCa progression during AS, and changes on MRI are not accurate enough to indicate PCa progression. There was a nonsignificant trend toward improved diagnostic estimates of PRECISE recommendations. These findings highlight the need to further define the optimal triggers and timing of biopsy during AS, as well as the need for optimizing the quality, interpretation, and reporting of serial prostate MRI.

PATIENT SUMMARY

Our study suggests that serial prostate magnetic resonance imaging (MRI) alone in patients on active surveillance is not accurate enough to reliably rule out or rule in prostate cancer progression. Other clinical factors and biomarkers along with serial MRI are required to safely tailor the intensity of follow-up biopsies.

MRI-targeted prostate biopsy: the next step forward!

Aim

For decades, the gold standard technique for diagnosing prostate cancer was the 10 to 12 core systematic transrectal or transperineal biopsy, under ultrasound guidance. Over the past years, an increased rate of false negative results and detection of clinically insignificant prostate cancer has been noted, resulting into overdiagnosis and overtreatment. The purpose of the current study was to evaluate the changes in diagnosis and management of prostate cancer brought by MRI-targeted prostate biopsy.

Methods

A critical review of literature was carried out using the Medline database through a PubMed search, 37 studies meeting the inclusion criteria: prospective studies published in the past 8 years with at least 100 patients per study, which used multiparametric magnetic resonance imaging as guidance for targeted biopsies.

Results

In-Bore MRI targeted biopsy and Fusion targeted biopsy outperform standard systematic biopsy both in terms of overall and clinically significant prostate cancer detection, and ensure a lower detection rate of insignificant prostate cancer, with fewer cores needed. In-Bore MRI targeted biopsy performs better than Fusion biopsy especially in cases of apical lesions.

Conclusion

Targeted biopsy is an emerging and developing technique which offers the needed improvements in diagnosing clinically significant prostate cancer and lowers the incidence of insignificant ones, providing a more accurate selection of the patients for active surveillance and focal therapies.

The impact of age on pathological insignificant prostate cancer rates in contemporary robot-assisted prostatectomy patients despite active surveillance eligibility

BACKGROUND

To assess insignificant prostate cancer(iPCa) rates after robot-assisted radical prostatectomy (RARP) in contemporary patients who were preoperatively eligible for active surveillance(AS). IPCa indicates no risk of PCa progression.

METHODS

We retrospectively analysed 2,837 RARP patients (2010-2019) who fulfilled at least one AS entry criteria set - Prostate Cancer Research International - Active Surveillance(PRIAS), University of California San Francisco(UCSF), National Comprehensive Cancer Network(NCCN) or University of Toronto. We utilized four different iPCa definitions, (1) based on pT2 and Gleason score ≤6 and also cumulative tumor-volume (2) ≤2.5mL, (3) ≤0.7mL or (4) ≤0.5mL. For each AS set we tested the rates of iPCa and compared between age <70 vs. ≥70 yrs. This was complemented by multivariable logistic regression(LRM) predicting iPCa, adjusted for age and clinical AS variables. Finally, within the subgroup, who had iPCa, we tested rate of those, who were deemed preoperatively AS ineligible.

RESULTS

Between most(PRIAS) and least stringent(TORONTO) AS sets, iPCa(1) was correctly predicted in 70-57%. Similarly, for iPCa definitions 2-4, rates were (2)59-42%, (3)34-19% and (4)27-14%. Senior patients harbored decreased proportions of iPCa. LRM confirmed that advanced age is associated with a lower chance of iPCa. More stringent AS sets lead to higher rates of AS ineligibility, e.g. 53% for PRIAS, despite iPCa.

CONCLUSIONS

AS sets show limited accuracy for stricter iPCa definitions, which further declined with advanced age. Greater AS stringency resulted in more AS ineligible patients despite harboring iPCa. In consequence, patients are at risk for overtreatment. Clinicians must consider age and different AS sets that result in highly variable detection rates of iPCa.

Atypical small acinar proliferation and its significance in pathological reports in modern urological times

Atypical small acinar proliferation is a histopathological diagnosis of unspecified importance in prostate needle-biopsy reports, suggestive but not definitive for cancer. The terminology corresponds to some uncertainty in the biopsy report, as the finding might represent an underlying non-cancerous pathology mimicking cancer or an under-sampled prostate cancer site. Therefore, traditional practice favors an immediate repeat biopsy. However, in modern urological times, the need of urgent repeat biopsy is being challenged by some authors as in the majority of cases, the grade of cancer found in subsequent biopsy is reported to be low or the disease to be non-significant. On the other hand, high risk disease cannot be excluded, whereas no clinical or pathological factors can predict the final outcome. In this review, we discuss the significance of the diagnosis of atypical small acinar proliferation in the biopsy report, commenting on its importance in modern urological practice.

The role of multiparametric magnetic resonance imaging in the selection and follow-up of patients undergoing active surveillance for prostate cancer. An European Section of Uro-Technology (ESUT) review

INTRODUCTION

In recent years, active surveillance (AS) has gained popularity as a safe and reasonable option for patients with low-risk, clinically localized prostate cancer.

OBJECTIVE

To summarize the latest information regarding the use of mpMRI in the setting of active surveillance (AS) for the management of prostate cancer (PCa).

EVIDENCE ACQUISITION

A PubMed-based, English literature search was conducted through February 2020. We selected the most relevant original articles, meta-analyses and systematic reviews that could provide important information.

EVIDENCE SYNTHESIS

The great importance of mpMRI of the prostate in the setting of PCa diagnosis is its ability to visualize primarily high-grade cancerous lesions potentially missed on systematic biopsies. In several studies, mpMRI has shown an improved performance over clinically based models for identifying candidates which will benefit the most from AS. Although data on prostate mpMRI during follow-up of men under AS is sparse, it holds the probability to improve significantly AS programs by a more precise selection of optimal candidates, a more accurate identification of disease progression and a reduction in number of biopsies. The goal of reassessment of patients undergoing AS is to find the most effective moment to change attitude to active treatment.

CONCLUSION

The value of mpMRI has been recognized due to its high negative predictive value (NPV) for lesion upgrading in low-risk PCa patients. The improvement in imaging detection, and precise diagnosis with mpMRI could reduce misclassifications at initial diagnosis and during follow-up, reducing the number of biopsies.

Comparison of Multiparametric Magnetic Resonance Imaging-Targeted Biopsy With Systematic Transrectal Ultrasonography Biopsy for Biopsy-Naive Men at Risk for Prostate Cancer: A Phase 3 Randomized Clinical Trial

Importance

Magnetic resonance imaging (MRI) with targeted biopsy is an appealing alternative to systematic 12-core transrectal ultrasonography (TRUS) biopsy for prostate cancer diagnosis, but has yet to be widely adopted.

Objective

To determine whether MRI with only targeted biopsy was noninferior to systematic TRUS biopsies in the detection of International Society of Urological Pathology grade group (GG) 2 or greater prostate cancer.

Design, Setting, and Participants

This multicenter, prospective randomized clinical trial was conducted in 5 Canadian academic health sciences centers between January 2017 and November 2019, and data were analyzed between January and March 2020. Participants included biopsy-naive men with a clinical suspicion of prostate cancer who were advised to undergo a prostate biopsy. Clinical suspicion was defined as a 5% or greater chance of GG2 or greater prostate cancer using the Prostate Cancer Prevention Trial Risk Calculator, version 2. Additional criteria were serum prostate-specific antigen levels of 20 ng/mL or less (to convert to micrograms per liter, multiply by 1) and no contraindication to MRI.

Interventions

Magnetic resonance imaging-targeted biopsy (MRI-TB) only if a lesion with a Prostate Imaging Reporting and Data System (PI-RADS), v 2.0, score of 3 or greater was identified vs 12-core systematic TRUS biopsy.

Main Outcome and Measures

The proportion of men with a diagnosis of GG2 or greater cancer. Secondary outcomes included the proportion who received a diagnosis of GG1 prostate cancer; GG3 or greater cancer; no significant cancer but subsequent positive MRI results and/or GG2 or greater cancer detected on a repeated biopsy by 2 years; and adverse events.

Results

The intention-to-treat population comprised 453 patients (367 [81.0%] White, 19 [4.2%] African Canadian, 32 [7.1%] Asian, and 10 [2.2%] Hispanic) who were randomized to undergo TRUS biopsy (226 [49.9%]) or MRI-TB (227 [51.1%]), of which 421 (93.0%) were evaluable per protocol. A lesion with a PI-RADS score of 3 or greater was detected in 138 of 221 men (62.4%) who underwent MRI, with 26 (12.1%), 82 (38.1%), and 30 (14.0%) having maximum PI-RADS scores of 3, 4, and 5, respectively. Eighty-three of 221 men who underwent MRI-TB (37%) had a negative MRI result and avoided biopsy. Cancers GG2 and greater were identified in 67 of 225 men (30%) who underwent TRUS biopsy vs 79 of 227 (35%) allocated to MRI-TB (absolute difference, 5%, 97.5% 1-sided CI, -3.4% to ∞; noninferiority margin, -5%). Adverse events were less common in the MRI-TB arm. Grade group 1 cancer detection was reduced by more than half in the MRI arm (from 22% to 10%; risk difference, -11.6%; 95% CI, -18.2% to -4.9%).

Conclusions and Relevance

Magnetic resonance imaging followed by selected targeted biopsy is noninferior to initial systematic biopsy in men at risk for prostate cancer in detecting GG2 or greater cancers.

Trial Registration

ClinicalTrials.gov Identifier: NCT02936258.

One-year experience of government-funded magnetic resonance imaging prior to prostate biopsy: A case for omitting biopsy in men with a negative magnetic resonance imaging

Objectives:

This study aimed to characterise the accuracy of multiparametric magnetic resonance imaging (mpMRI) as an adjunct to prostate biopsy, and to assess the effect of the new Australian Medicare rebate on practice at a metropolitan public hospital.

Patients and methods:

We identified patients who underwent transrectal ultrasound (TRUS)-guided prostate biopsy at a single institution over a two-year period. Patients were placed into two groups, depending upon whether their consent was obtained before or after the introduction of the Australian Medicare rebate for mpMRI. We extracted data on mpMRI results and TRUS-guided biopsy histopathology. Descriptive statistics were used to demonstrate baseline patient characteristics as well as MRI and histopathology results.

Results:

A total of 252 patients were included for analysis, of whom 128 underwent biopsy following the introduction of the Medicare rebate for mpMRI. There was a significant association between Prostate Imaging Reporting and Data System v2 (PI-RADS) classification and the diagnosis of clinically significant prostate cancer ( p<0.01). Only one man with PI-RADS ⩽2 was found to have clinically significant prostate cancer. Four men with a PI-RADS 3 lesion were found to have clinically significant cancer. A PI-RADS 4 or 5 lesion was significantly associated with the diagnosis of clinically significant cancer on multivariable analysis.

Conclusion:

mpMRI is an important adjunct to biopsy in the diagnosis of clinically significant prostate cancer. Our findings support the safety of omitting/delaying prostate biopsy in men with negative mpMRI.

Level of evidence:

Level 3 retrospective case-control study.

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.

Detection limits of significant prostate cancer using multiparametric MR and digital rectal examination in men with low serum PSA: Up-date of the Italian Society of Integrated Diagnostic in Urology

Reasons why significant prostate cancer is still missed in early stage were investigated at the 22nd National SIEUN (Italian Society of integrated diagnostic in Urology, Andrology, Nephrology) congress took place from 30th November to 1st December 2020, in virtual modality. Even if multiparametric magnetic resonance (MR) has been introduced in the clinical practice several, limitations are emerging in patient with regular digital rectal examination (DRE) and serum prostate specific antigen (PSA) levels approaching the normal limits. The present paper summarizes highlights observed in those cases where significant prostate cancer may be missed by PSA or imaging and DRE. The issue of multidisciplinary interest had been subdivided and deepened under four main topics: biochemical, clinical, pathological and radiological point of view with a focus on PI-RADS 3 lesions.

[Machine learning and multiparametric MRI for early diagnosis of prostate cancer]

In the last few years, the early diagnosis of prostate cancer has continued to shift from systematic biopsies to multiparametric MRI (mpMRI)-guided/MRI-transrectal ultrasound (TRUS) fusion biopsies and guidelines are already reflecting these changes. While MRI-TRUS fusion biopsies have already resulted in significant improvements in diagnostic sensitivity and, thus, correct diagnosis of clinically significant prostate cancer (sPC), its use to avoid biopsies in certain men is still controversial. Optimal use of mpMRI requires a high degree of reader expertise due to the difficulty of image interpretation and poses the problem of training sufficient numbers of radiologists while demand is increasing. Recently, artificial intelligence (AI) has been utilized to create fully automatic analysis tools for interpretation of mpMRI of the prostate, rivaling the performance of clinical radiologist interpretation in retrospective research studies, demonstrating the promising potential of AI for diagnostic prostate MRI in the future. This article will provide an overview of machine and deep learning and its application in mpMRI of the prostate for early diagnosis of prostate cancer.

Clash of the calculators: External validation of prostate cancer risk calculators in men undergoing mpMRI and transperineal biopsy

Objective

To compare the accuracy of the European Randomized Study of Screening for Prostate Cancer (ERSPC) RC, MRI‐ERSPC‐RC, and Prostate Biopsy Collaborative Group (PBCG) RC in patients undergoing transperineal prostate biopsy.

Patients and methods

We identified 392 patients who underwent mpMRI before transperineal prostate biopsy across multiple public and private institutions between January 2017 and August 2019. The estimated probabilities of detecting PCa and significant PCa were calculated using the MRI‐ERSPC‐RC, ERSPC‐RC, and PBCG‐RC. Receiver operating characteristic (ROC) curves for each calculator were generated and the area underneath the curve (AUC) was compared. Calibration and clinical utility were assessed with calibration plots and decision curve analysis, respectively.

Results

PCa was detected in 285 patients (72.7%) with significant PCa found in 200 patients (51.1%). ROC curve analysis found the MRI‐ERSPC‐RC outperformed the ERSPC‐RC and PBCG‐RC. For the prediction of PCa, the AUC was 0.756, 0.696, and 0.675 for the MRI‐ERSPC‐RC, ERSPC‐RC, and PBCG‐RC, respectively. The AUC for the prediction of significant PCa was 0.803, 0.745, and 0.746 for the MRI‐ERSPC‐RC, ERSPC‐RC, and PBCG‐RC, respectively.

Conclusions

Our study validated the ERSPC‐RC, MRI‐ERSPC‐RC, and PBCG‐RC in a cohort undergoing transperineal prostate biopsy with the MRI‐ERSPC‐RC performing the best. These RCs may enable improved shared decision making and help to guide patient selection for biopsy.