Multiparametric magnetic resonance imaging and follow-up to avoid prostate biopsy in 4259 men

Prostate cancer risk assessment and avoidance of prostate biopsies using fully automatic deep learning in prostate MRI: comparison to PI-RADS and integration with clinical data in nomograms

OBJECTIVES

Risk calculators (RCs) improve patient selection for prostate biopsy with clinical/demographic information, recently with prostate MRI using the prostate imaging reporting and data system (PI-RADS). Fully-automated deep learning (DL) analyzes MRI data independently, and has been shown to be on par with clinical radiologists, but has yet to be incorporated into RCs. The goal of this study is to re-assess the diagnostic quality of RCs, the impact of replacing PI-RADS with DL predictions, and potential performance gains by adding DL besides PI-RADS.

MATERIAL AND METHODS

One thousand six hundred twenty-seven consecutive examinations from 2014 to 2021 were included in this retrospective single-center study, including 517 exams withheld for RC testing. Board-certified radiologists assessed PI-RADS during clinical routine, then systematic and MRI/Ultrasound-fusion biopsies provided histopathological ground truth for significant prostate cancer (sPC). nnUNet-based DL ensembles were trained on biparametric MRI predicting the presence of sPC lesions (UNet-probability) and a PI-RADS-analogous five-point scale (UNet-Likert). Previously published RCs were validated as is; with PI-RADS substituted by UNet-Likert (UNet-Likert-substituted RC); and with both UNet-probability and PI-RADS (UNet-probability-extended RC). Together with a newly fitted RC using clinical data, PI-RADS and UNet-probability, existing RCs were compared by receiver-operating characteristics, calibration, and decision-curve analysis.

RESULTS

Diagnostic performance remained stable for UNet-Likert-substituted RCs. DL contained complementary diagnostic information to PI-RADS. The newly-fitted RC spared 49% [252/517] of biopsies while maintaining the negative predictive value (94%), compared to PI-RADS ≥ 4 cut-off which spared 37% [190/517] (p < 0.001).

CONCLUSIONS

Incorporating DL as an independent diagnostic marker for RCs can improve patient stratification before biopsy, as there is complementary information in DL features and clinical PI-RADS assessment.

CLINICAL RELEVANCE STATEMENT

For patients with positive prostate screening results, a comprehensive diagnostic workup, including prostate MRI, DL analysis, and individual classification using nomograms can identify patients with minimal prostate cancer risk, as they benefit less from the more invasive biopsy procedure.

KEY POINTS

The current MRI-based nomograms result in many negative prostate biopsies. The addition of DL to nomograms with clinical data and PI-RADS improves patient stratification before biopsy. Fully automatic DL can be substituted for PI-RADS without sacrificing the quality of nomogram predictions. Prostate nomograms show cancer detection ability comparable to previous validation studies while being suitable for the addition of DL analysis.

Multiparametric Prostate MRI Accuracy of Prostate Imaging Reporting and Data System (v2.1) Scores 4 and 5: The Influence of Image Quality According to the Prostate Imaging Quality Score

Purpose: The accuracy of multiparametric magnetic resonance imaging (mpMRI) heavily relies on image quality, as evidenced by the evolution of the prostate imaging quality (PI-QUAL) scoring system for the evaluation of clinically significant prostate cancer (csPC). This study aims to evaluate the impact of PI-QUAL scores in detecting csPC within PI-RADS 4 and 5 lesions. Methods: We retrospectively selected from our database all mpMRI performed from January 2019 to March 2022. Inclusion criteria were as follows: (1) mpMRI acquired in our institution according to the technical requirements from the PI-RADS (v2.1) guidelines; (2) single lesion scored as PI-RADS (v2.1) 4 or 5; (3) MRI-TBx performed in our institution; (4) complete histology report; and (5) complete clinical record. Results: A total of 257 male patients, mean age 70.42 ± 7.6 years, with a single PI-RADS 4 or 5 lesion undergoing MRI-targeted biopsy, were retrospectively studied. Of these, 61.5% were PI-RADS 4, and 38.5% were PI-RADS 5, with 84% confirming neoplastic cells. In high-quality image lesions (PI-QUAL ≥ 4), all PI-RADS 5 lesions were accurately identified as positive at the final histological examination (100% of CDR). For PI-RADS 4 lesions, 37 (23%) were negative, resulting in a cancer detection rate of 77% (95% CI: 67.51-84.83). Conclusions: The accuracy of mpMRI, independently of the PI-RADS score, progressively decreased according to the decreasing PI-QUAL score. These findings emphasize the crucial role of the PI-QUAL scoring system in evaluating PI-RADS 4 and 5 lesions, influencing mpMRI accuracy.

Cancer Detection Rate and Abnormal Interpretation Rate of Prostate MRI Performed for Clinical Suspicion of Prostate Cancer

PURPOSE

To report cancer detection rate (CDR) and abnormal interpretation rate (AIR) in prostate MRI performed for clinical suspicion of prostate cancer (PCa).

MATERIALS AND METHODS

This retrospective single-institution, three-center study included patients who underwent MRI for clinical suspicion of PCa between 2017 and 2021. Patients with known PCa were excluded. Patient-level Prostate Imaging-Reporting and Data System (PI-RADS) score was extracted from the radiology report. AIR was defined as number of abnormal MRI (PI-RADS score 3-5) / total number of MRIs. CDR was defined as number of clinically significant PCa (csPCa: Gleason score ≥7) detected at abnormal MRI / total number of MRI. AIR, CDR, and CDR adjusted for pathology confirmation rate were calculated for each of three centers and pre-MRI biopsy status (biopsy-naive and previous negative biopsy).

RESULTS

A total of 9,686 examinations (8,643 unique patients) were included. AIR, CDR, and CDR adjusted for pathology confirmation rate were 45.4%, 23.8%, and 27.6% for center I; 47.2%, 20.0%, and 22.8% for center II; and 42.3%, 27.2%, and 30.1% for center III, respectively. Pathology confirmation rate ranged from 81.6% to 88.0% across three centers. AIR and CDR for biopsy-naive patients were 45.5% to 52.6% and 24.2% to 33.5% across three centers, respectively, and those for previous negative biopsy were 27.2% to 39.8% and 11.7% to 14.2% across three centers, respectively.

CONCLUSION

We reported CDR and AIR in prostate MRI for clinical suspicion of PCa. CDR needs to be adjusted for pathology confirmation rate and pre-MRI biopsy status for interfacility comparison.

Application of a validated prostate MRI deep learning system to independent same-vendor multi-institutional data: demonstration of transferability

OBJECTIVES

To evaluate a fully automatic deep learning system to detect and segment clinically significant prostate cancer (csPCa) on same-vendor prostate MRI from two different institutions not contributing to training of the system.

MATERIALS AND METHODS

In this retrospective study, a previously bi-institutionally validated deep learning system (UNETM) was applied to bi-parametric prostate MRI data from one external institution (A), a PI-RADS distribution-matched internal cohort (B), and a csPCa stratified subset of single-institution external public challenge data (C). csPCa was defined as ISUP Grade Group ≥ 2 determined from combined targeted and extended systematic MRI/transrectal US-fusion biopsy. Performance of UNETM was evaluated by comparing ROC AUC and specificity at typical PI-RADS sensitivity levels. Lesion-level analysis between UNETM segmentations and radiologist-delineated segmentations was performed using Dice coefficient, free-response operating characteristic (FROC), and weighted alternative (waFROC). The influence of using different diffusion sequences was analyzed in cohort A.

RESULTS

In 250/250/140 exams in cohorts A/B/C, differences in ROC AUC were insignificant with 0.80 (95% CI: 0.74-0.85)/0.87 (95% CI: 0.83-0.92)/0.82 (95% CI: 0.75-0.89). At sensitivities of 95% and 90%, UNETM achieved specificity of 30%/50% in A, 44%/71% in B, and 43%/49% in C, respectively. Dice coefficient of UNETM and radiologist-delineated lesions was 0.36 in A and 0.49 in B. The waFROC AUC was 0.67 (95% CI: 0.60-0.83) in A and 0.7 (95% CI: 0.64-0.78) in B. UNETM performed marginally better on readout-segmented than on single-shot echo-planar-imaging.

CONCLUSION

For same-vendor examinations, deep learning provided comparable discrimination of csPCa and non-csPCa lesions and examinations between local and two independent external data sets, demonstrating the applicability of the system to institutions not participating in model training.

CLINICAL RELEVANCE STATEMENT

A previously bi-institutionally validated fully automatic deep learning system maintained acceptable exam-level diagnostic performance in two independent external data sets, indicating the potential of deploying AI models without retraining or fine-tuning, and corroborating evidence that AI models extract a substantial amount of transferable domain knowledge about MRI-based prostate cancer assessment.

KEY POINTS

• A previously bi-institutionally validated fully automatic deep learning system maintained acceptable exam-level diagnostic performance in two independent external data sets. • Lesion detection performance and segmentation congruence was similar on the institutional and an external data set, as measured by the weighted alternative FROC AUC and Dice coefficient. • Although the system generalized to two external institutions without re-training, achieving expected sensitivity and specificity levels using the deep learning system requires probability thresholds to be adjusted, underlining the importance of institution-specific calibration and quality control.

Reliability of prostate imaging reporting and data system version 2.1 for excluding clinically significant prostate cancer using a 1.5 tesla scanner

INTRODUCTION

Multiparametric magnetic resonance imaging (mpMRI) of the prostate gland is now the recommended initial investigation of choice for the detection of Prostate cancer (PCa). It effectively identifies patients who require prostate biopsies due to the risk of clinically significant PCa. It helps patients with clinically insignificant PCa avoid the invasive biopsies and possible accompanying complications. Large clinical trials have investigated the accuracy of mpMRI in detecting PCa. We performed a local review to examine the reliability of omitting tissue sampling in men with a negative (PIRADS 2 (P2) or less) mpMRI in the primary diagnostic setting.

METHODS

This was a retrospective study of patients with clinical suspicion of PCa within a 2-year period. Patients had a mpMRI prior to having trans-perineal prostate gland biopsies. Clinically significant disease was defined as Gleason 7 and above. The descriptive data was analysed using contingency table methods. A p-value less than 0.05 was statistically significant.

RESULTS

Out of 700 patients 90 had an mpMRI score of PIRADS 2. Seventy-seven (85.5%) of these patients had a negative biopsy, 9(10%) showed Gleason 6, 4 patients showed Gleason 7 or above. 78 patients with PIRADS 2 had a PSA density of < 0.15, none of which had a clinically significant biopsy result. The negative predictive value of mpMRI from this study is 95%.

CONCLUSION

Our results are in line with negative predictive values demonstrated in the current literature. This local study, likely applicable to other district general hospitals, shows that mpMRI is a safe and reliable initial investigation to aid decisions on which patients require biopsies.

[Prostate biopsy-infection prophylaxis and patient preparation]

Prostate biopsy has been at the center of controversy in recent years due to high infection complications associated with the transrectal route and the withdrawal of authorization for fluoroquinolones and fosfomycin trometemol as prophylaxis. The Urological Infections Guideline Group of the European Association of Urology (EAU) recently published a meta-analysis in two parts based on randomized controlled trials (RCTs) and annually updates the data for the EAU guidelines. The meta-analyses show that transperineal prostate biopsy is associated with significantly fewer infectious complications than transrectal biopsy and should therefore be preferred. If transrectal biopsy is still used, then intrarectal cleansing with povidone-iodine and antibiotic prophylaxis should be used. Antibiotic prophylaxis strategies include targeted prophylaxis after sensitivity testing of the rectal flora, augmented prophylaxis with several antibiotics and empirical monoprophylaxis. Data from RCTs are available for aminoglycosides and third-generation cephalosporins.

Natural History of Patients with Prostate MRI Likert 1-3 and Development of RosCaP: a Multivariate Risk Score for Clinically Significant Cancer

INTRODUCTION

Clinically significant prostate cancer (csCaP) with Gleason ≥3 + 4 is found in 10% negative prebiopsy multiparametric (mp) MRI cases and varies widely for equivocal mpMRI cases. The objective of this study was to investigate long-term outcomes of patients with negative and equivocal mpMRIs and to develop a predictive score for csCaP risk stratification in this group.

PATIENTS AND METHODS

Patients who underwent an upfront mpMRI between May 2015 and March 2018 with an MRI score Likert 1 to 3 were included in the study. Patients had either a CaP diagnosis at MRI-targeted biopsy or were not diagnosed and attended follow-up in the community. Outcomes were analysed through the Kaplan-Meier estimator and Cox Model. Regression coefficients of significant variables were used to develop a Risk of significant Cancer of the Prostate score (RosCaP).

RESULTS

At first assessment 281/469 patients had mpMRI only and 188/469 mpMRI and biopsy, 26 csCaP were found at biopsy, including 10/26 in Likert 3 patients. 12/371 patients discharged without CaP after first assessment were diagnosed with csCaP during a median of 34.2 months' follow-up, 11/12 diagnosis occurred in patients omitting initial biopsy. csCaP diagnosis-free survival was 95.7% in the MRI group and 99.1% in the biopsy group. From these outcomes, a continuous RosCaP score was developed: RosCaP = 0.083 x Age - 0.202 x (1/PSA Density) + 0.786 (if Likert 3), and 4 risk classes were proposed. Limitations include retrospective design and absence of external validation.

CONCLUSION

Age, PSA Density and MRI Likert score were significantly associated to the risk of csCaP and utilised to devise the novel RosCap predictive score focused to support risk assessment in patients with negative or equivocal mpMRI results.

Landmarks in the evolution of prostate biopsy

Approaches and techniques used for diagnostic prostate biopsy have undergone considerable evolution over the past few decades: from the original finger-guided techniques to the latest MRI-directed strategies, from aspiration cytology to tissue core sampling, and from transrectal to transperineal approaches. In particular, increased adoption of transperineal biopsy approaches have led to reduced infectious complications and improved antibiotic stewardship. Furthermore, as image fusion has become integral, these novel techniques could be incorporated into prostate biopsy methods in the future, enabling 3D-ultrasonography fusion reconstruction, molecular targeting based on PET imaging and autonomous robotic-assisted biopsy.

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%.

Patient- and tumor-level risk factors for MRI-invisible prostate cancer

BACKGROUND

Multiparametric MRI is highly sensitive for detection of clinically significant prostate cancer, but has a 10-20% false negative rate. It is unknown if there are clinical factors that predict MRI invisibility. We sought to identify predictors of MRI-invisible (MRI(-)) disease.

METHODS

Men undergoing MRI/US-fusion targeted + systematic biopsy by two surgeons at our institution from 2015 to 2018 were reviewed. Patient demographics, clinical data, MRI metrics, and biopsy pathology results were obtained by chart review. An MRI(-) tumor was defined as a positive systematic biopsy in a zone without an MRI lesion. Factors associated with presence of MRI(-) tumors were identified using stepwise multivariable logistic regression.

RESULTS

Of 194 men included in the analysis, 79 (41%) and 25 (13%) men had GG1+ and GG2+ MRI(-) tumors, respectively. On multivariable analysis, only Black race was associated with presence of GG1+ MRI(-) tumors (OR 2.2, 95% CI 1.02-4.96). Black race (OR 3.5, 95% CI 1.24-9.87) and higher PSA density (OR 2.0, 95% CI 1.34-3.20) were associated with presence of GG2+ MRI(-) tumors. In non-Black and Black men, detection of MRI(-) tumors on systematic biopsy upgraded patients from no disease to GG2+ disease 1% and 11% of the time, respectively, and from GG1 to GG2+ disease 42% and 60% of the time, respectively.

CONCLUSIONS

Black race and PSA density were associated with presence of MRI(-) prostate cancer. Further study on racial differences is warranted based on these results. Surgeons should consider pre-biopsy risk factors before deciding to omit systematic prostate biopsy regardless of mpMRI results.

Clinical implementation of pre-biopsy magnetic resonance imaging pathways for the diagnosis of prostate cancer

Objective

To assess the outcomes of pre‐biopsy magnetic resonance imaging (MRI) pathways, as a tool in biopsy‐naïve men with suspicion of prostate cancer, in routine clinical practice. Secondary outcomes included a comparison of transrectal MRI‐directed biopsy (TR‐MRDB) and transperineal (TP)‐MRDB in men with suspicious MRI.

Patients and Methods

We retrospectively assessed a two‐centre cohort of consecutive biopsy‐naïve men with suspicion of prostate cancer who underwent a Prostate Imaging‐Reporting and Data System version 2 (PI‐RADS v2) compliant pre‐biopsy MRI in a single, high‐volume centre between 2015 and 2019 (Centre 1). Men with suspicious MRI scans underwent TR‐MRDB in Centre 1 and TP‐MRDB with additional random biopsies (RB) in Centre 2. The MRI and histopathology were assessed in the same institution (Centre 1). Outcomes included: (i) overall detection rates of Grade Group (GG) 1, GG ≥2, and GG ≥3 cancer in men with suspicious MRI; (ii) Biopsy‐avoidance due to non‐suspicious MRI; and (iii) Cancer detection rates and biopsy‐related complications between TR‐ and TP‐MRDB. To reduce confounding bias for MRDB comparisons, inverse probability weighting (IPW) was performed for age, digital rectal examination, prostate‐specific antigen (PSA), prostate volume, PSA density, and PI‐RADS category.

Results

Of the 2597 men included, the overall GG 1, GG ≥2, and GG ≥3 prevalence was 8% (210/2597), 27% (697/2597), and 15% (396/2597), respectively. Biopsy was avoided in 57% (1488/2597) of men. After IPW, the GG 1, GG ≥2 and GG ≥3 detection rates after TR‐ and TP‐MRDB were comparable at 24%, 57%, and 32%; and 18%, 64%, and 38%, respectively; with mean differences of −5.7% (95% confidence interval [CI] −13% to 1.4%), 6.1% (95% CI −2.1% to 14%), and 5.7% (95% CI −1.7% to 13%). Complications were similar in TR‐MRDB (0.50%) and TP‐MRDB with RB (0.62%; mean difference 0.11%, 95% CI −0.87% to 1.1%).

Conclusion

This high‐volume, two‐centre study shows pre‐biopsy MRI as a decision tool is implementable in daily clinical practice. Compared to recent trials, a substantially higher biopsy avoidance rate was achieved without compromising GG ≥2/GG ≥3 detection and coinciding with lower over detection rates of GG 1 cancer. Prostate cancer detection and complication rates were comparable for TR‐ and TP‐MRDB.

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.

[Prostate biopsy 2021: current management]

Infectious complications following prostate biopsy are on the rise due to an increase in antimicrobial resistance, mainly against fluoroquinolones. The use of fluoroquinolones for perioperative prophylaxis is no longer approved by the national authorities in Germany. The EAU guideline group on urological infections has recently published a meta-analysis in two parts based on randomised controlled trials (RCTs). Transperineal prostate biopsy is associated with a significantly reduced rate of infectious complications compared with transrectal biopsy and should therefore be preferred. If transrectal biopsy is performed, intrarectal cleaning with povidone-iodine and antibiotic prophylaxis without fluoroquinolones should be chosen. Antibiotic prophylactic strategies include targeted prophylaxis after susceptibility testing of the rectal flora, augmented prophylaxis with multiple antibiotics and empiric mono-prophylaxis with non-fluoroquinolones. Data from RCTs are available for aminoglycosides, third-generation cephalosporins and fosfomycin trometamol.

Predictive clinical features for negative histopathology of MRI/Ultrasound-fusion-guided prostate biopsy in patients with high likelihood of cancer at prostate MRI: Analysis from a urologic outpatient clinic1

OBJECTIVE

The aim of this study was to evaluate clinical features associated with benign histopathology of Prostate Imaging Reporting and Data System (PI-RADS) category 4 and 5 lesions.

MATERIALS AND METHODS

Between March 2015 and November 2020, 1161 patients underwent mpMRI/Ultrasound-fusion-guided prostate biopsy (FBx) and concurrent 12-core systematic prostate biopsy (SBx) at the Department of Urology of the Ludwig-Maximilians-University of Munich, Germany. 848/ 1161 (73%) patients presented with either PI-RADS 4 or 5 index lesion and were retrospectively evaluated. Multivariate analysis was performed to evaluate clinical parameters associated with a negative outcome of PI-RADS 4 or 5 category lesions after FBx. Area under the receiver operating characteristics (ROC) curve (AUC) was conducted using ROC-analysis.

RESULTS

676/848 (79.7%) patients with either PI-RADS 4 or 5 index lesion were diagnosed with prostate cancer (PCa) by FBx and 172/848 (20.3%) patients had a negative biopsy (including the concurrent systematic prostate biopsy), respectively. Prostate volume (P-Vol) (OR 0.99, 95% CI = 0.98-1.00, p = 0.038), pre-biopsy-status (OR 0.48, 95% CI = 0.29-0.79, p = 0.004) and localization of the lesion in the transitional zone (OR 0.28, 95% CI = 0.13-0.60, p = 0.001) were independent risk factors for a negative outcome of FBx. Age (OR 1.09, 95% CI = 1.05-1.13, p < 0.001) and PSA density (PSAD) (OR 75.92, 95% CI = 1.03-5584.61, p = 0.048) increased the risk for PCa diagnosis after FBx. The multivariate logistic regression model combining all clinical characteristics achieved an AUC of 0.802 (95% CI = 0.765-0.835; p < 0.001) with a sensitivity and specificity of 66% and 85%.

CONCLUSION

Lesions with high or highly likelihood of PCa on multiparametric magnetic resonance imaging (mpMRI) but subsequent negative prostate biopsy occur in a small amount of patients. Localization of the lesion in the transitional zone, prostate volume and prebiopsy were shown to be predictors for benign histopathology of category 4 or 5 lesions on mpMRI. Integration of these features into daily clinical routine could be used for risk-stratification of these patients after negative biopsy of PI-RADS 4 or 5 index lesions.

Delivering Clinical impacts of the MRI diagnostic pathway in prostate cancer diagnosis

Pre-biopsy multiparametric MRI is now recommended by multiple guidelines, not only for men with persistent suspicion of prostate cancer after prior negative systematic biopsy, but also at initial screening before the first biopsy. The major benefit of pre-biopsy MRI in the diagnostic work-up is to promote individualized risk-adapted approaches for biopsy-decision management. Multiple MRI-directed diagnostic pathways can be conceived, with each approach having net-benefit trade-offs between benefits and harms, based on improved diagnostic yields of significant cancers and reduced biopsy testing and reduced detection of indolent prostate cancer. In this paper, we illustrate how clinical benefits can be maximized in men with MRI-negative and MRI-positive results, using the PI-RADS Multiparametric MRI and MRI-directed biopsy pathway. From a practice perspective, we emphasize five golden rules: (1) that multiparametric MRI approach including targeted biopsies be reserved for men likely to benefit from early detection and treatment of prostate cancer; (2) that there is a need to carefully assess risk of significant disease using PSA and clinical parameters before and after MRI; (3) do not offer immediate biopsy if the MRI is negative, unless other high-risk factors are present; (4) accept that not all significant cancers are found immediately and have robust 'safety nets' for men with negative MRI scans who avoid immediate biopsy and for positive MRI patients with negative or non-explanatory histology; and (5) use MRI-directed biopsy methods that minimize overdiagnosis and improve risk stratification.

European Association of Urology Position Paper on the Prevention of Infectious Complications Following Prostate Biopsy

The transperineal approach is preferred to reduce prostate biopsy (PB)-related infections. Fluoroquinolones are suspended for prophylaxis of PB in the European Union; therefore, alternative antibiotics based on local resistance, or targeted prophylaxis, in conjunction with povidone-iodine rectal preparation are recommended for transrectal PB.

[Infectious complications following prostate biopsy-Major changes 2020]

BACKGROUND

Infectious complications following prostate biopsy are increasing and fluoroquinolone prophylaxis has recently been suspended in Germany by the national authorities.

OBJECTIVES

This review is intended to highlight current strategies for reducing infectious complications following prostate biopsy.

MATERIALS AND METHODS

The European Association of Urology (EAU) guideline group on urological infections recently published a meta-analysis in two parts based on randomized controlled trials (RCTs). The most important contents shall be presented here.

RESULTS

Transperineal prostate biopsy is associated with significantly reduced infectious complications than transrectal biopsy. If transrectal biopsy is performed, intrarectal cleaning with povidone-iodine and antibiotic prophylaxis without fluoroquinolones should be chosen. Antibiotic prophylactic strategies include targeted prophylaxis after susceptibility testing of the rectal flora, augmented prophylaxis with multiple antibiotics and empiric monoprophylaxis with nonfluoroquinolones. Here data from RCTs are available for aminoglycosides, third generation cephalosporines, and fosfomycin trometamol.

CONCLUSIONS

The transperineal approach is preferred to reduce prostate biopsy-related infections. Fluoroquinolones are no longer approved for prophylaxis. Thus, alternative antibiotics based on local resistance, or targeted prophylaxis, in conjunction with povidone-iodine rectal preparation are recommended for transrectal prostate biopsy.

Expected impact of MRI-related interreader variability on ProScreen prostate cancer screening trial: a pre-trial validation study

BACKGROUND

The aim of this study is to investigate the potential impact of prostate magnetic resonance imaging (MRI) -related interreader variability on a population-based randomized prostate cancer screening trial (ProScreen).

METHODS

From January 2014 to January 2018, 100 men aged 50-63 years with clinical suspicion of prostate cancer (PCa) in Helsinki University Hospital underwent MRI. Nine radiologists individually reviewed the pseudonymized MRI scans of all 100 men in two ProScreen trial centers. All 100 men were biopsied according to a histological composite variable comprising radical prostatectomy histology (N = 38) or biopsy result within 1 year from the imaging (N = 62). Fleiss' kappa (κ) was used to estimate the combined agreement between all individual radiologists. Sample data were subsequently extrapolated to 1000-men subgroups of the ProScreen cohort.

RESULTS

Altogether 89% men of the 100-men sample were diagnosed with PCa within a median of 2.4 years of follow-up. Clinically significant PCa (csPCa) was identified in 76% men. For all PCa, mean sensitivity was 79% (SD ±10%, range 62-96%), and mean specificity 60% (SD ±22%, range 27-82%). For csPCa (Gleason Grade 2-5) MRI was equally sensitive (mean 82%, SD ±9%, range 67-97%) but less specific (mean 47%, SD ±20%, range 21-75%). Interreader agreement for any lesion was fair (κ 0.40) and for PI-RADS 4-5 lesions it was moderate (κ 0.60). Upon extrapolating these data, the average sensitivity and specificity to a screening positive subgroup of 1000 men from ProScreen with a 30% prevalence of csPCa, 639 would be biopsied. Of these, 244 men would be true positive, and 395 false positive. Moreover, 361 men would not be referred to biopsy and among these, 56 csPCas would be missed. The variation among the radiologists was broad as the least sensitive radiologist would have twice as many men biopsied and almost three times more men would undergo unnecessary biopsies. Although the most sensitive radiologist would miss only 2.6% of csPCa (false negatives), the least sensitive radiologist would miss every third.

CONCLUSIONS

Interreader agreement was fair to moderate. The role of MRI in the ongoing ProScreen trial is crucial and has a substantial impact on the screening process.

MRI-targeted or systematic random biopsies for prostate cancer diagnosis in biopsy naïve patients: follow-up of a PRECISION trial-like retrospective cohort

BACKGROUND

To test clinically significant prostate cancer (csPCa) rates during follow-up in biopsy naïve patients that underwent two different diagnostic pathways: (1) SB GROUP (n = 354): systematic random biopsies (SB) vs. (2) TB GROUP (n = 264): multiparametric magnetic resonance imaging (mpMRI) and only targeted biopsies (TB) of PI-RADS ≥ 3 lesions. Patients with PI-RADS ≤ 2 score avoided prostate biopsies.

METHODS

Retrospective single centre study of 618 biopsy naive patients (2015-2018). Two different definitions of csPCa were used: (1) csPCa ISUP GG ≥ 2 (ISUP grade group [GG] ≥ 2) and (2) csPCa ISUP GG ≥ 3. Kaplan-Meier plots and univariable Cox regression models tested rates over time of csPCa ISUP GG ≥ 2 and caPCa ISUP GG ≥ 3 in SB GROUP vs. TB GROUP.

RESULTS

At initial biopsy, TB achieved higher rates of csPCa ISUP GG ≥ 2 (35.3 vs. 18.9%; p < 0.001) and csPCa ISUP GG ≥ 3 (12.6 vs. 6.2%; p = 0.04), relative to SB. After a median time follow-up of 36 months, the rates of csPCa ISUP GG ≥ 2 (6.1 vs. 4.4%; p = 0.6) and csPCa ISUP GG ≥ 3 (3.3 vs. 1.1%; p = 0.2) were similar in SB GROUP vs. TB GROUP. Moreover, in TB GROUP patients that avoided prostate biopsies because of negative baseline mpMRI (n = 145), only 4.1% exhibited csPCa ISUP GG ≥ 2 during follow-up. Moreover, none of these patients (PI-RADS ≤ 2) had csPCa ISUP GG ≥ 3.

CONCLUSIONS

In biopsy naïve setting, a diagnostic pathway including pre-biopsy mpMRI and TB of only PCa suspicious lesions is not associated with higher rates of csPCa during follow-up, relative to a diagnostic pathway of SB. Moreover, patients with negative baseline mpMRI could safely avoid prostate biopsies and could be followed with repeated PSA testing, since only a small proportion of them would harbor csPCa.

Efficacy of 3T Multiparametric MR Imaging followed by 3T in-Bore MR-Guided Biopsy for Detection of Clinically Significant Prostate Cancer Based on PIRADSv2.1 Score

PURPOSE

To evaluate the diagnostic yield of 3T in-Bore magnetic resonance-guided biopsy (3T IB-MRGB) for detection of clinically significant prostate cancer (csPCa), based on assessment using the Prostate Imaging Reporting and Data System version 2.1 (PIRADSv2.1).

MATERIALS AND METHODS

This single-center study examined individuals who underwent 3T multiparametric prostate magnetic resonance (MR) imaging and subsequent 3T IB-MRGB. The final study cohort included 379 men (with 475 targets) divided into 3 subcohorts: biopsy-naïve men (n = 123), individuals with a history of negative trans-rectal-ultrasonography (TRUS) biopsy results (n = 106), and men with low-grade PCa under active surveillance (n = 150). csPCa was defined as having a Gleason score (GS) ≥3+4.

RESULTS

3T IB-MRGB detected PCa and csPCa in 69.1% (262 of 379) and 50.3% (193 of 379) of patients, respectively. The PCa and csPCa detection rates per target were 64.2% (305 of 475) and 43.8% (208 of 475), respectively. The rate of urosepsis, treated with intravenous antibiotics, was 1% (4 patients). In TRUS biopsy negative results and biopsy-naïve subcohorts, csPCa was found in 36.8% (39 of 106) and 52.8% (65 of 123), respectively. In 50.7% (76 of 150) of the active surveillance subcohort, 3T IB-MRGB upgraded the GS assigned in prior TRUS biopsies. Positive predictive values of PIRADSv2.1 categories 3, 4, and 5 for csPCa detection were 24.8%, 44.4%, and 67.1%, respectively. Higher PIRADSv2.1 categories were significantly associated with PCa (odds ratio [OR], 3.97; 95% confidence interval [CI], 2.98-5.28) and csPCa (OR, 1.41; 95% CI, 1.03-1.94) detection. Of 137 PIRADSv2 category 3 lesions, 28 were downgraded to PIRADSv2.1 category 2, in which there were no occurrences of csPCa in histology.

CONCLUSIONS

Use of 3T IB-MRGB resulted in detection of csPCa in 50.9% of individuals. 3T IB-MRGB has a high diagnostic yield in individuals with negative TRUS biopsy results and those under active surveillance. The PIRADSv2.1 category is a strong predictor of PCa and csPCa detection.

Diagnostic yields in patients with suspected prostate cancer undergoing MRI as the first-line investigation in routine practice

AIM

To document cancer yields of magnetic resonance imaging (MRI)-directed biopsies in men with suspected prostate cancer referred to secondary care.

MATERIALS AND METHODS

Men with suspected cancer undergoing multiparametric prostate MRI as the first-line investigation were included in the present study. Systematic transrectal prostate biopsies with/without cognitive targeted biopsies were performed. Diagnostic yields of International Society of Urological Pathology (ISUP) ≥2 cancers by the Prostate Imaging Reporting and Data System (PI-RADS) category were recorded. Impacts of prostate-specific antigen (PSA) density on biopsy results and yields of non-targeted biopsies in MRI non-suspicious prostate sextants assessed.

RESULTS

Of 262 men (90.5% biopsy naive), 86 (33%) MRI examinations were negative (PI-RADS 1-2) and 176 (67%) positive (PI-RADS 3: 8%; PI-RADS 4: 21%; PI-RADS 5: 38%). Two hundred and thirteen of 262 patients underwent a biopsy. ISUP ≥2 cancer detection rates were 8% (5/61) for PI-RADS 1-2, 18% (3/17) for PI-RADS 3, 49% (22/45) for PI-RADS 4, and 80% (72/90) for PI-RADS 5. Proportions of ISUP ≥2 increased with higher PSA densities in positive patients (%ISUP ≥2 for PSA density groups <0.12, 0.12 to <0.15 and ≥ 0.15 was 0%, 0%, 25% for PI-RADS 3, 21%, 33%, 68% for PI-RADS 4 and 40%, 83%, 89% for PI-RADS 5 respectively). ISUP ≥2 cancers were twice as likely in tumour adjacent sextants (52% versus 24%), without upgrading of gland level histology from insignificant to clinically significant prostate cancer by the sampling of normal-appearing tumour non-adjacent sextants.

CONCLUSIONS

One third of men can avoid biopsy after negative MRI. Cancer detection rates increase with PSA density values within positive MRI suspicion categories. Sampling normal-appearing tumour non-adjacent sextants may be unnecessary for whole-gland therapy.

Multiparametric magnetic resonance imaging and multiparametric magnetic resonance imaging-guided biopsy in the diagnostic pathway of prostate cancer

Multiparametric magnetic resonance imaging (mpMRI) of the prostate and mpMRI-guided biopsy have proved to be a valuable part of the diagnostic pathway for prostate cancer. This review reports on the current results in terms of clinical performance of these diagnostic tools and their role in clinical decision-making.

Associations of PTEN and ERG with Magnetic Resonance Imaging Visibility and Assessment of Non-organ-confined Pathology and Biochemical Recurrence After Radical Prostatectomy

BACKGROUND

Diagnosing clinically significant prostate cancer (PCa) is challenging, but may be facilitated by biomarkers and multiparametric magnetic resonance imaging (MRI).

OBJECTIVE

To determine the association between biomarkers phosphatase and tensin homolog (PTEN) and ETS-related gene (ERG) with visible and invisible PCa lesions in MRI, and to predict biochemical recurrence (BCR) and non-organ-confined (non-OC) PCa by integrating clinical, MRI, and biomarker-related data.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective analysis of a population-based cohort of men with PCa, who underwent preoperative MRI followed by radical prostatectomy (RP) during 2014-2015 in Helsinki University Hospital (n = 346), was conducted. A tissue microarray corresponding to the MRI-visible and MRI-invisible lesions in RP specimens was constructed and stained for PTEN and ERG.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Associations of PTEN and ERG with MRI-visible and MRI-invisible lesions were examined (Pearson's χ² test), and predictions of non-OC disease together with clinical and MRI parameters were determined (area under the receiver operating characteristic curve and logistic regression analyses). BCR prediction was analyzed by Kaplan-Meier and Cox proportional hazard analyses.

RESULTS AND LIMITATIONS

Patients with MRI-invisible lesions (n = 35) had less PTEN loss and ERG-positive expression compared with patients (n = 90) with MRI-visible lesions (17.2% vs 43.3% [p = 0.006]; 8.6% vs 20.0% [p = 0.125]). Patients with invisible lesions had better, but not statistically significantly improved, BCR-free survival probability in Kaplan-Meier analyses (p = 0.055). Rates of BCR (5.7% vs 21.1%; p = 0.039), extraprostatic extension (11.4% vs 44.6%; p < 0.001), seminal vesicle invasion (0% vs 21.1%; p = 0.003), and lymph node metastasis (0% vs 12.2%; p = 0.033) differed between the groups in favor of patients with MRI-invisible lesions. Biomarkers had no independent role in predicting non-OC disease or BCR. The short follow-up period was a limitation.

CONCLUSIONS

PTEN loss, BCR, and non-OC RP findings were more often encountered with MRI-visible lesions.

PATIENT SUMMARY

Magnetic resonance imaging (MRI) of the prostate misses some cancer lesions. MRI-invisible lesions seem to be less aggressive than MRI-visible lesions.

Prostate cancer screening research can benefit from network medicine: an emerging awareness

Up to date, screening for prostate cancer (PCa) remains one of the most appealing but also a very controversial topics in the urological community. PCa is the second most common cancer in men worldwide and it is universally acknowledged as a complex disease, with a multi-factorial etiology. The pathway of PCa diagnosis has changed dramatically in the last few years, with the multiparametric magnetic resonance (mpMRI) playing a starring role with the introduction of the “MRI Pathway”. In this scenario the basic tenet of network medicine (NM) that sees the disease as perturbation of a network of interconnected molecules and pathways, seems to fit perfectly with the challenges that PCa early detection must face to advance towards a more reliable technique. Integration of tests on body fluids, tissue samples, grading/staging classification, physiological parameters, MR multiparametric imaging and molecular profiling technologies must be integrated in a broader vision of “disease” and its complexity with a focus on early signs. PCa screening research can greatly benefit from NM vision since it provides a sound interpretation of data and a common language, facilitating exchange of ideas between clinicians and data analysts for exploring new research pathways in a rational, highly reliable, and reproducible way.

Prostate biopsy techniques and pre-biopsy prophylactic measures: variation in current practice patterns in the Netherlands

BACKGROUND

The clinical landscape of prostate biopsy (PB) is evolving with changes in procedures and techniques. Moreover, antibiotic resistance is increasing and influences the efficacy of pre-biopsy prophylactic regimens. Therefore, increasing antibiotic resistance may impact on clinical care, which probably results in differences between hospitals. The objective of our study is to determine the (variability in) current practices of PB in the Netherlands and to gain insight into Dutch urologists' perceptions of fluoroquinolone resistance and biopsy related infections.

METHODS

An online questionnaire was prepared using SurveyMonkey® platform and distributed to all 420 members of the Dutch Association of Urology, who work in 81 Dutch hospitals. Information about PB techniques and periprocedural antimicrobial prophylaxis was collected. Urologists' perceptions regarding pre-biopsy antibiotic prophylaxis in an era of antibiotic resistance was assessed. Descriptive statistical analysis was performed.

RESULTS

One hundred sixty-one responses (38.3%) were analyzed representing 65 (80.3%) of all Dutch hospitals performing PB. Transrectal ultrasound guided prostate biopsy (TRUSPB) was performed in 64 (98.5%) hospitals. 43.1% of the hospitals (also) used other image-guided biopsy techniques. Twenty-three different empirical prophylactic regimens were reported among the hospitals. Ciprofloxacin was most commonly prescribed (84.4%). The duration ranged from one pre-biopsy dose (59.4%) to 5 days extended prophylaxis. 25.2% of the urologists experienced ciprofloxacin resistance as a current problem in the prevention of biopsy related infections and 73.6% as a future problem.

CONCLUSIONS

There is a wide variation in practice patterns among Dutch urologists. TRUSPB is the most commonly used biopsy technique, but other image-guided biopsy techniques are increasingly used. Antimicrobial prophylaxis is not standardized and prolonged prophylaxis is common. The wide variation in practice patterns and lack of standardization underlines the need for evidence-based recommendations to guide urologists in choosing appropriate antimicrobial prophylaxis for PB in the context of increasing antibiotic resistance.