Why and Where do We Miss Significant Prostate Cancer with Multi-parametric Magnetic Resonance Imaging followed by Magnetic Resonance-guided and Transrectal Ultrasound-guided Biopsy in Biopsy-naïve Men?

Transperineal prostate biopsy: The modern gold standard to prostate cancer diagnosis

In patients suspicious for prostate cancer, a prostate biopsy should be performed. Biopsies are possible either by the transrectal or transperineal routes. Compared with the transrectal prostate biopsy (TRPBx), transperineal prostate biopsy (TPPBx) offers a non-inferior cancer detection rate (CDR), especially in patients undergoing re-biopsy for persistently elevated PSA and in cases of active surveillance (AS), in which TPPBx seems to be superior. Moreover, the transperineal route achieves superior sampling of the anterior and apical regions, especially after previous multiple negative TRPBx. Infectious complications are nullified due to avoidance of needle passage through the rectal mucosa, and there is a highly significant evidence of reduced fever and sepsis rates when compared with TRPBx, with maintaining acceptable urinary retention rates. This is an important upcoming topic due to the increasing antibiotic resistance rates, thus reducing periinterventional hospitalization and health care costs. To date, TPPBx is perfectly feasible in the inpatient and out-patient settings and under local anesthesia, characterized by a moderate learning curve and a good reproducibility. By applying mpMRI as a diagnostic tool, clinically significant prostate cancer (csPCa) detection seems to be comparable to transrectal MRI-fusion biopsy (TR-MRIFBx). Finally, focal treatment of localized disease is currently performed exclusively through a TP approach.

Negative Predictive Value of Multiparametric Magnetic Resonance Imaging in the Detection of Clinically Significant Prostate Cancer in the Prostate Imaging Reporting and Data System Era: A Systematic Review and Meta-analysis

CONTEXT

Prebiopsy multiparametric magnetic resonance imaging (mpMRI) is increasingly used in prostate cancer diagnosis. The reported negative predictive value (NPV) of mpMRI is used by some clinicians to aid in decision making about whether or not to proceed to biopsy.

OBJECTIVE

We aim to perform a contemporary systematic review that reflects the latest literature on optimal mpMRI techniques and scoring systems to update the NPV of mpMRI for clinically significant prostate cancer (csPCa).

EVIDENCE ACQUISITION

We conducted a systematic literature search and included studies from 2016 to September 4, 2019, which assessed the NPV of mpMRI for csPCa, using biopsy or clinical follow-up as the reference standard. To ensure that studies included in this analysis reflect contemporary practice, we only included studies in which mpMRI findings were interpreted according to the Prostate Imaging Reporting and Data System (PIRADS) or similar Likert grading system. We define negative mpMRI as either (1) PIRADS/Likert 1-2 or (2) PIRADS/Likert 1-3; csPCa was defined as either (1) Gleason grade group ≥2 or (2) Gleason grade group ≥3. We calculated NPV separately for each combination of negative mpMRI and csPCa.

EVIDENCE SYNTHESIS

A total of 42 studies with 7321 patients met our inclusion criteria and were included for analysis. Using definition (1) for negative mpMRI and csPCa, the pooled NPV for biopsy-naïve men was 90.8% (95% confidence interval [CI] 88.1-93.1%). When defining csPCa using definition (2), the NPV for csPCa was 97.1% (95% CI 94.9-98.7%). Calculation of the pooled NPV using definition (2) for negative mpMRI and definition (1) for csPCa yielded the following: 86.8% (95% CI 80.1-92.4%). Using definition (2) for both negative mpMRI and csPCa, the pooled NPV from two studies was 96.1% (95% CI 93.4-98.2%).

CONCLUSIONS

Multiparametric MRI of the prostate is generally an accurate test for ruling out csPCa. However, we observed heterogeneity in the NPV estimates, and local institutional data should form the basis of decision making if available.

PATIENT SUMMARY

The negative predictive values should assist in decision making for clinicians considering not proceeding to biopsy in men with elevated age-specific prostate-specific antigen and multiparametric magnetic resonance imaging reported as negative (or equivocal) on Prostate Imaging Reporting and Data System/Likert scoring. Some 7-10% of men, depending on the setting, will miss a diagnosis of clinically significant cancer if they do not proceed to biopsy. Given the institutional variation in results, it is of upmost importance to base decision making on local data if available.

The Value of Prostate-Specific Antigen-Related Indexes and Imaging Screening in the Diagnosis of Prostate Cancer

Objective

The aim of this study was to explore the value of the prostate-specific antigen (PSA) levels, the ratio of free PSA to total PSA (fPSA/TPSA), the PSA density (PSAD), digital rectal examination (DRE), transrectal prostate ultrasound (TRUS), and multiparameter MRI (MP-MRI) in the differential diagnosis of benign prostatic hyperplasia (BPH) and prostate cancer (PCa).

Methods

From February 2016 to September 2019, data from 620 patients who underwent systematic transrectal ultrasound-guided prostate biopsy (STURS-PB) in our hospital were retrospectively collected, including the PSA levels, the fPSA/TPSA ratio, the PSAD, DRE, TRUS, MP-MRI, prostate volume, and other clinical data.

Results

Among the 620 patients, 249 patients were in the PCa group, and 371 patients in the BPH group. The positive puncture rate was 40.16%. The positive predictive values of DRE, TRUS, mpMRI, and TPSA levels for PCa were 39.91%, 39.38%, 64.14%, and 41.57%, respectively; the sensitivity of these parameters was 37.35%, 51.41%, 74.69%, and 57.43%, respectively; and the specificity of these parameters was 62.26%, 46.90%, 71.97%, and 45.82%, respectively. When the TPSA concentration was in the range of 4-20 ng/mL, the positive puncture rate of STURS-PB was 23.18%, with a high rate of misdiagnosis. When the TPSA concentration was in the range of 4-20 ng/mL, the fPSA/TPSA ratio was 0.15, the PSAD was 0.16, the comprehensive evaluation of PCa was optimal (the sensitivity of these parameters was 88.85% and 84.09%, respectively; the specificity was 80.17% and 67.29%, respectively; the positive predictive value was 57.41% and 51.39%, respectively). When the TPSA concentration >4 ng/mL, the fPSA/TPSA ratio ≤0.15 and the PSAD ≥0.16, the sensitivity, specificity, and correctness index of the PCa and BPH diagnosis were 80.54%, 82.75%, and 67.07%, respectively.

Conclusion

When using DRE, TRUS, and MP-MRI to screen for PCa, MP-MRI has a relatively high sensitivity and specificity. Using these three thresholds (TPSA >4 ng/mL combined with an fPSA/TPSA ratio ≤0.15 and a PSAD ≥0.16) is significantly better than using TPSA levels alone for the differential diagnosis of PCa and BPH.

Current Status of MRI and PET in the NCCN Guidelines for Prostate Cancer

Prostate cancer (PCa) represents a significant source of morbidity and mortality for men in the United States, with approximately 1 in 9 being diagnosed with PCa in their lifetime. The role of imaging in the evaluation of men with PCa has evolved and currently plays a central role in diagnosis, treatment planning, and evaluation of recurrence. Appropriate use of multiparametric MRI (mpMRI) and MRI-guided transrectal ultrasound (MR-TRUS) biopsy increases the detection of clinically significant PCa while decreasing the detection of clinically insignificant PCa. This process may help patients with clinically insignificant PCa avoid the adverse effects of unnecessary therapy. In the setting of a known PCa, patients with low-grade disease can be observed using active surveillance, which often includes a combination of prostate-specific antigen (PSA) testing, serial mpMRI, and, if indicated, follow-up systematic and targeted TRUS-guided tissue sampling. mpMRI can provide important information in the posttreatment setting, but PET/CT is creating a paradigm shift in imaging standards for patients with locally recurrent and metastatic PCa. This article examines the strengths and limitations of mpMRI for initial PCa diagnosis, active surveillance, recurrent disease evaluation, and image-guided biopsies, and the use of PET/CT imaging in men with recurrent PCa. The goal of this review is to provide a rational basis for current NCCN Clinical Practice Guidelines in Oncology for PCa as they pertain to the use of these advanced imaging modalities.

Rethinking prostate cancer screening: could MRI be an alternative screening test?

In the past decade rigorous debate has taken place about population-based screening for prostate cancer. Although screening by serum PSA levels can reduce prostate cancer-specific mortality, it is unclear whether the benefits outweigh the risks of false-positive results and overdiagnosis of insignificant prostate cancer, and it is not recommended for population-based screening. MRI screening for prostate cancer has the potential to be analogous to mammography for breast cancer or low-dose CT for lung cancer. A number of potential barriers and technical challenges need to be overcome in order to implement such a programme. We discuss different approaches to MRI screening that could address these challenges, including abbreviated MRI protocols, targeted MRI screening, longer rescreening intervals and a multi-modal screening pathway. These approaches need further investigation, and we propose a phased stepwise research framework to ensure proper evaluation of the use of a fast MRI examination as a screening test for prostate cancer.

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

OBJECTIVES

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

A deep dive into understanding tumor foci classification using multiparametric MRI based on convolutional neural network

PURPOSE

Deep learning models have had a great success in disease classifications using large data pools of skin cancer images or lung X-rays. However, data scarcity has been the roadblock of applying deep learning models directly on prostate multiparametric MRI (mpMRI). Although model interpretation has been heavily studied for natural images for the past few years, there has been a lack of interpretation of deep learning models trained on medical images. In this paper, an efficient convolutional neural network (CNN) was developed and the model interpretation at various convolutional layers was systematically analyzed to improve the understanding of how CNN interprets multimodality medical images and the predictive powers of features at each layer. The problem of small sample size was addressed by feeding the intermediate features into a traditional classification algorithm known as weighted extreme learning machine (wELM), with imbalanced distribution among output categories taken into consideration.

METHODS

The training data collection used a retrospective set of prostate MR studies, from SPIE-AAPM-NCI PROSTATEx Challenges held in 2017. Three hundred twenty biopsy samples of lesions from 201 prostate cancer patients were diagnosed and identified as clinically significant (malignant) or not significant (benign). All studies included T2-weighted (T2W), proton density-weighted (PD-W), dynamic contrast enhanced (DCE) and diffusion-weighted (DW) imaging. After registration and lesion-based normalization, a CNN with four convolutional layers were developed and trained on tenfold cross validation. The features from intermediate layers were then extracted as input to wELM to test the discriminative power of each individual layer. The best performing model from the tenfolds was chosen to be tested on the holdout cohort from two sources. Feature maps after each convolutional layer were then visualized to monitor the trend, as the layer propagated. Scatter plotting was used to visualize the transformation of data distribution. Finally, a class activation map was generated to highlight the region of interest based on the model perspective.

RESULTS

Experimental trials indicated that the best input for CNN was a modality combination of T2W, apparent diffusion coefficient (ADC) and DWI_b50 . The convolutional features from CNN paired with a weighted extreme learning classifier showed substantial performance compared to a CNN end-to-end training model. The feature map visualization reveals similar findings on natural images where lower layers tend to learn lower level features such as edges, intensity changes, etc, while higher layers learn more abstract and task-related concept such as the lesion region. The generated saliency map revealed that the model was able to focus on the region of interest where the lesion resided and filter out background information, including prostate boundary, rectum, etc. CONCLUSIONS: This work designs a customized workflow for the small and imbalanced dataset of prostate mpMRI where features were extracted from a deep learning model and then analyzed by a traditional machine learning classifier. In addition, this work contributes to revealing how deep learning models interpret mpMRI for prostate cancer patient stratification.

Making a case "against" focal therapy for intermediate-risk prostate cancer

INTRODUCTION

Focal therapy (FT) for localized prostate cancer (PCa) is a promising treatment strategy. Although, according to guidelines, it should be regarded as an experimental option, its introduction into clinical practice has occurred at an accelerated speed. It is, thus, crucial for Urologists to understand FT limitations and potential drawbacks that may derive from its use.

METHODS

We performed a literature search of peer-reviewed English language articles using Pubmed and the words "focal therapy" AND "prostate cancer" to identify relevant articles. Web search was complemented by manual search.

RESULTS

From a biological perspective, in contrast with the index lesion theory, which still needs to be better supported, PCa is a multifocal and multiclonal entity. Also, the effects of FT on PCa microenvironment are unclear. From a clinical perspective, patient selection is still not precisely defined. Even when all variables potentially decreasing mpMRI and biopsy accuracy are optimized, up to one out of two men may be incorrectly selected for FT, leaving a significant proportion of clinically significant PCa (csPCa) untreated. Underestimation of PCa volume and variant histologies are other additional mpMRI potential limitations. No RCTs have been performed against the standard of care to support FT. There is absence of long-term results and FT series reaching medium-term follow-up have non-optimal oncological control with significant re-treatment needs. When PCa recurs/persists after FT, little is known about the appropriate management strategies and their outcomes. Finally, the optimal follow-up scheme post-FT remains unclear.

CONCLUSIONS

Several arguments are present against the use of FT for localized PCa. Studies are needed to overcome current limitations and support FT before it can be included as part of the standard management of prostate cancer.

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

OBJECTIVES

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Targeted Biopsy With Reduced Number of Cores: Optimal Sampling Scheme in Patients Undergoing Magnetic Resonance Imaging/Transrectal Ultrasound Fusion Prostate Biopsy

The 3 Tesla (3T) magnetic resonance imaging (MRI) combined ultrasound (TRUS) targeted biopsy plus 12-core systematic biopsy (TBx + 12-SBx) was considered a reliable method for prostate cancer (PCa) diagnosis. To find another optimal sampling scheme with fewer cores and the same efficiency as TBx + 12-SBx for prostate biopsy, 113 patients who underwent five different hypothetical sampling schemes were analyzed and compared with TBx + 12-SBx. The detection rates of targeted biopsy plus 6-core lateral systematic biopsy (TBx + lateral 6-SBx) for PCa and clinically significant prostate cancer (csPCa) (99.1% and 96.4%, respectively) were higher than other schemes, and the area under the receiver operating characteristic curve of TBx + lateral 6-SBx for PCa and csPCa (0.991 and 0.990, respectively) were also significantly higher than other sampling schemes except TBx plus 6-core ipsilateral systematic biopsy (TBx + ipsilateral 6-SBx). Additionally, TBx + lateral 6-SBx had the lowest missed diagnosis rate. Thus, the TBx + lateral 6-SBx may be the optimal scheme for patients undergoing MRI/TRUS fusion prostate biopsy.

Influence of the Location and Zone of Tumor in Prostate Cancer Detection and Localization on 3-T Multiparametric MRI Based on PI-RADS Version 2

OBJECTIVE. The objective of our study was to determine the performance of 3-T multiparametric MRI (mpMRI) for prostate cancer (PCa) detection and localization, stratified by anatomic zone and level, using Prostate Imaging Reporting and Data System version 2 (PI-RADSv2) and whole-mount histopathology (WMHP) as reference. MATERIALS AND METHODS. Multiparametric MRI examinations of 415 consecutive men were compared with thin-section WMHP results. A genitourinary radiologist and pathologist collectively determined concordance. Two radiologists assigned PI-RADSv2 scores and sector location to all detected foci by consensus. Tumor detection rates were calculated for clinical and pathologic (tumor location and zone) variables. Both rigid and adjusted sector-matching models were used to account for fixation-related issues. RESULTS. Of 863 PCa foci in 16,185 prostate sectors, the detection of overall and index PCa lesions in the midgland, base, and apex was 54.9% and 83.1%, 42.1% and 64.0% (p = 0.04, p = 0.02), and 41.9% and 71.4% (p = 0.001, p = 0.006), respectively. Tumor localization sensitivity was highest in the midgland compared with the base and apex using an adjusted match compared with a rigid match (index lesions, 71.3% vs 43.7%; all lesions, 70.8% vs 36.0%) and was greater in the peripheral zone (PZ) than in the transition zone. Three-Tesla mpMRI had similarly high specificity (range, 93.8-98.3%) for overall and index tumor localization when using both rigid and adjusted sector-matching approaches. CONCLUSION. For 3-T mpMRI, the highest sensitivity (83.1%) for detection of index PCa lesions was in the midgland, with 98.3% specificity. Multiparametric MRI performance for sectoral localization of PCa within the prostate was moderate and was best for index lesions in the PZ using an adjusted model.

Contrast-enhanced ultrasound with dispersion analysis for the localization of prostate cancer: correlation with radical prostatectomy specimens

PURPOSE

To determine the value of two-dimensional (2D) contrast-enhanced ultrasound (CEUS) imaging and the additional value of contrast ultrasound dispersion imaging (CUDI) for the localization of clinically significant prostate cancer (csPCa).

METHODS

In this multicentre study, subjects scheduled for a radical prostatectomy underwent 2D CEUS imaging preoperatively. CUDI maps were generated from the CEUS recordings. Both CEUS recordings and CUDI maps were scored on the likelihood of presenting csPCa (any Gleason ≥ 4 + 3 and Gleason 3 + 4 larger than 0.5 mL) by five observers and compared to radical prostatectomy histopathology. An automated three-dimensional (3D) fusion protocol was used to match imaging with histopathology. Receiver operator curve (ROC) analysis was performed per observer and imaging modality.

RESULTS

133 of 216 (62%) patients were included in the final analysis. Average area under the ROC for all five readers for CEUS, CUDI and the combination was 0.78, 0.79 and 0.78, respectively. This yields a sensitivity and specificity of 81 and 64% for CEUS, 83 and 56% for CUDI and 83 and 55% for the combination. Interobserver agreement for CEUS, CUDI and the combination showed kappa values of 0.20, 0.18 and 0.18 respectively.

CONCLUSION

The sensitivity and specificity of 2D CEUS and CUDI for csPCa localization are moderate. Despite compressing CEUS in one image, CUDI showed a similar performance to 2D CEUS. With a sensitivity of 83% at cutoff point 3, it could become a useful imaging procedure, especially with 4D acquisition, improved quantification and combination with other US imaging techniques such as elastography.

Investigating the equivalent performance of biparametric compared to multiparametric MRI in detection of clinically significant prostate cancer

PURPOSE

PIRADS v2 stipulates that dynamic contrast-enhanced (DCE) imaging be used to categorize diffusion-weighted-imaging (DWI) score 3 (DWI 3) peripheral zone (PZ) lesions as PIRADS score 3 (PIRADS 3; DCE -) or PIRADS 4 (DCE +). It's controversial for the value of DCE in improving clinically significant prostate cancer (csPCa) detection. We aimed to figure out whether DCE improves csPCa detection and explore new available measures to improve csPCa detection.

PATIENTS AND METHODS

We retrospectively enrolled 375 patients who underwent mp MRI before MRI/ultrasound (US) fusion-targeted biopsy (TB) with transperineal systematic biopsy (SB). All lesions were classified as DWI 3/DCE -, DWI 3/DCE +, DWI 4/PIRADS 4 lesions. Detection rates of csPCa for each lesion group were analyzed. The diagnostic performance of each approach was analyzed by receiver operating characteristics (ROC) analysis and decision curve analysis.

RESULTS

Totally, 109 DWI 3 or DWI 4 single lesions in PZ were analyzed (n = 109). The rates of csPCa detection for Group A, Group B, Group C is 10.3%, 13.9%, 55.9%, respectively (A vs. B, p = 0.625; B vs. C, p < 0.001). ROC analysis and decision curve analysis showed the method of combining Age, PSA Density (PSAD) and the mean apparent diffusion coefficient value (ADC_mean) outperforms individual approaches for csPCa detection.

CONCLUSION

For DWI 3 lesions in PZ, DCE sequence has not additional value for improving detection of csPCa. The integration of clinical characteristics and bpMRI parameter improves the detection of csPCa.

A noninferiority within-person study comparing the accuracy of transperineal to transrectal MRI-US fusion biopsy for prostate-cancer detection

BACKGROUND

Magnetic resonance imaging (MRI) and ultrasound (US) fusion prostate-biopsies can be performed in a transrectal (TR-fusion) or transperineal (TP-fusion) approach. Prospective comparative evidence is limited. In this study we compared the detection rate of clinically-significant prostate-cancer (csPCa) within an index lesion between TR and TP-fusion.

PATIENTS AND METHODS

This was a prospective, noninferiority, and within-person trial. Men scheduled for MRI-US-fusion with a discrete MRI PI-RRAD ≥ 3 lesion were included. A dominant index lesion was determined for each subject and sampled by TR and TP-fusion during the same session. The order of biopsies was randomized and equipment was reset to avoid chronological and incorporation bias. For each subject, the index lesion was sampled 4-6 times in each approach. All biopsies were performed using Navigo fusion software (UC-Care, Yokneam, Israel). csPCa was defined as: Grade Group ≥ 2 or cancer-core length ≥ 6 mm. We used a noninferiority margin of 10% and a one-sided alpha level of 5%.

RESULTS

Seventy-seven patients completed the protocol. Median age was 68.2 years (IQR:64.2-72.2), median PSA was 8.9 ng/ml (IQR:6.18-12.2). Ten patients (13%) were biopsy naive, others (87%) had a previous biopsy. csPCa was detected in 32 patients (42%). All of these cases were detected by TP-fusion, while only 20 (26%) by TR-fusion. Absolute difference for csPCa diagnosis was 15.6 (CI 90% 27.9-3.2%) in favor of TP-fusion (p = 0.029). TP-fusion was noninferior to TR-fusion. The lower boundary of the 90% confidence-interval between TP-fusion and TR-fusion was greater than zero, therefore TP-fusion was also found to be superior. Exploratory subgroup analyses showed TP-fusion was consistently associated with higher detection rates of csPCa compared with TR-fusion in patient and index-lesion derived subgroups (size, location, PI-RADS, PSA, and biopsy history).

CONCLUSIONS

In this study, TP-fusion biopsies were found to be noninferior and superior to TR-fusion biopsies in detecting csPCa within MRI-visible index lesion. Centers experienced in both TP and TR-fusion should consider these results when choosing biopsy method.

Assessment of the Minimal Targeted Biopsy Core Number per MRI Lesion for Improving Prostate Cancer Grading Prediction

Background: To study the impact of MRI characteristics and of targeted biopsy (TB) core number on the final grade group (GG) prediction. Materials and Methods: The cohort was 478 consecutive patients who underwent radical prostatectomy (RP) after positive mpMRI (multiparametric magnetic resonance imaging) followed by fusion TB. Endpoints were the upgrading and concordance rates between TB and RP specimens. Results: Upgrading rate after TB was 40.6%. Patients with upgrading had lower PIRADS (Prostate Imaging-Reporting and Data System) scores (p < 0.001), smaller lesion size (p = 0.017), fewer TB cores (p < 0.001), and lower TB density (p = 0.015) compared with cases with grade concordance. There was a significant continuous improvement in upgrading rate when TB core number per lesion increased from 56.3% to 25.6% when <2 or ≥5 TB cores were taken, respectively (p = 0.002). The minimal TB number per lesion to reduce upgrading risk to approximately 30%was 4 in PIRADS 3, and 3 in PIRADS 4–5 cases. Conclusions: Grade group prediction by TB is significantly improved by higher PIRADS score, larger lesion size, and increased TB per lesion. At least four TB cores should be taken in PIRADS 3 score lesions, whereas three cores seem enough in PIRADS 4–5 cases to improve GG prediction and limit upgrading risk.

Additive Value of Transrectal Systematic Ventral Biopsies in Combination with Magnet Resonance Imaging/Ultrasound Fusion-Guided Biopsy in Patients with 3 or More Negative Prostate Biopsies

INTRODUCTION

Patients with consistent suspicion for prostate cancer (PCa) and multiple negative prebiopsies prior to multiparametric magnetic resonance imaging (mpMRI) are still frequently evaluated for an image-guided biopsy and are reported with heterogeneous detection rates. The inclusion of a systematic biopsy (SB) is also still recommended with predominant sampling within the posterior/peripheral zone of the prostate. The aim of this study was (I) to evaluate PCa detection rates using a modified 10 core SB template including anterior biopsies in combination with mpMRI/ultrasound fusion-guided targeted biopsy (TB) in patients with 3 or more negative prebiopsies and (II) to compare mpMRI index lesion localization with histologically confirmed locali-zation from associated prostatectomy samples.

METHODS

Overall 1,337 consecutive patients underwent sensor-based registration TB of the prostate and a subsequent 10-core SB between January 2012 and December 2015 at our institution. For this study, 101 patients with ≥3 negative prebiopsies and prostate imaging - reporting data system lesions ≥3 were pooled prospectively and underwent TB and a modified SB including 2 ventral (anterior) biopsies. Detection rates were estimated for the modified SB, TB, and its combination. A subgroup analysis of 35 patients undergoing prostatectomy was performed by a head-to-head comparison of mpMRI index lesion and histologically confirmed PCa index lesion localization.

RESULTS

The overall detection rate for PCa was 54.5%. The combination of TB and SB detected 14 (25.4%) more cases missed by TB alone (p < 0.001) and 7 (12.7%) more cases missed by SB alone (p = 0.016), respectively. A postoperative Gleason upgrade was seen in 12/35 (34.3%) cases within the TB group and in 14/35 (40.0%) in the SB group, respectively. The subgroup analysis showed a predominant location of PCa index lesions anteriorly at the level of the midgland. The MRI detection rate of the anteriorly located index lesions was 70.4% (15/21 cases) with a clinically significant Gleason score (≥3 + 4 = 7a [International Society of Urological Pathology grade 2]) in 80.9%. Interestingly a modified SB template detected 90.5% (19/21) of the anteriorly located index lesions.

CONCLUSION

Our data suggest that in patients with multiple prebiopsies PCa seems to be predominantly located anteriorly. We suggest the general integration of anterior biopsies despite TB in repeat biopsy patients.

Comparison of prostate cancer detection rates between magnetic resonance imaging-targeted biopsy and transrectal ultrasound-guided biopsy according to Prostate Imaging Reporting and Data System in patients with PSA ≥4 ng/mL: a systematic review and meta-analysis

Background

Previous studies have investigated magnetic resonance imaging-targeted biopsy (MRI-TBx) on the detection for prostate cancer (PCa). Prostate Imaging Reporting and Data System (PI-RADS), as a standardized MRI reporting system, has widely been used in the management of PCa. However, basing the PI-RADS score, the comparability between MRI-TBx and transrectal ultrasound-guided biopsy (TRUS-Bx) in diagnosing PCa remained inconsistent or even controversial. Thus, this systematic meta-analysis aimed to assess the value of PI-RADS in sifting better prostate biopsy method.

Methods

A meta-analysis including 10 articles was performed. In these included studies, biopsy-naive subjects with concerning PSA levels and/or an abnormal digital rectal examination (DRE) were consecutively enrolled by referral from urologists. All subjects underwent multiparameter MRI (mpMRI) prostate and the results were scored independently by PI-RADS. Subjects with equivocal (PI-RADS 3) and intermediate/high-risk (PI-RADS 4/5) lesions underwent MRI-TBx and followed by TRUS-Bx performed by a urologist. The online databases PubMed, Embase and Web of Science were searched to find all correlated articles until October 1^st, 2019. Data were pooled by odds ratios (ORs) with 95% confidence intervals (CIs) to assess the strength of the associations. Subgroup analyses were conducted based on Gleason score.

Results

Overall, 10 studies were included in this meta-analysis from January, 2015 to June, 2019. In the comparison of the detection of MRI-TBx and TRUS-Bx in PCa patients, TRUS-Bx had a significant advantage in overall PCa detection compared with MRI-TBx (OR =0.78, 95% CI: 0.62-0.98) in PI-RADS 3. Basing subgroup analysis of Gleason score (csPCa: Gleason score ≥7; non-csPCa: Gleason score <7), a summary analysis of the detection rate of csPCa showed that no significant difference was found (OR =0.82, 95% CI: 0.58-1.16); Meanwhile, no significant difference in non-csPCa patients was also detected (OR =0.83, 95% CI: 0.53-1.28). In PI-RADS 4 or 5, no significant results were detected between MRI-TBx and TRUS-Bx (OR =0.96, 95% CI: 0.87-1.06) for overall PCa detection. The stratification analyses by Gleason score found that TRUS-Bx had an advantage over MRI-TBx in non-csPCa patients (OR =0.76, 95% CI: 0.60-0.98); However, there was no significant difference in the detection rate of csPCa (OR =1.05, 95% CI: 0.93-1.20).

Conclusions

This meta-analysis indicated that using TRUS-Bx was better than MRI-TBx for the diagnosis of PCa in PI-RADS 3; Besides, TRUS-Bx have an advantage over MRI-TBx in the detection for non-csPCa in PI-RADS 4 or 5. Therefore, PI-RADS could be used as a MRI evaluation system in the selection of prostate biopsy.

[Importance of magnetic resonance imaging/ultrasound-guided fusion biopsy for the detection and monitoring of prostate cancer]

The use of multiparametric magnetic resonance imaging (mpMRI) is becoming increasingly more important for the primary diagnostics of prostate cancer (PCa) and for monitoring under active surveillance. Current studies confirmed that the use of mpMRI can increase the detection of clinically significant PCa and reduce the detection rate of insignificant PCa as well as the rate of unnecessary biopsies. The information from mpMRI can be cognitively used for in-bore biopsy and using fusion biopsy systems. There are no clear recommendations on the access approach for fusion biopsy (e. g. transrectal or perineal), whereby higher rates of rectal bleeding and infections have been described for transrectal access compared to perineal access. The increasing rate of antibiotic resistance as well as restricted indications for the use of quinolones are a major challenge for transrectal biopsy.

A comparison of magnetic resonance imaging techniques used to secure biopsies in prostate cancer patients

Introduction: Prostate cancer (PCa) is the most common diagnosed malignancy among the male population in the United States. The incidence is increasing with an estimated amount of 175.000 cases in 2019. Areas covered: Primarily, PCa is generally detected by an elevated or rising serum prostate-specific antigen (PSA) and digital rectal examination (DRE) followed by pathological examination. Histopathology ultimately confirms the presence of PCa and determines a Gleason score. However, PSA and DRE have low specificity and sensitivity, respectively. Subsequently, accurate assessment of the aggressiveness of PCa is essential to prevent overdiagnosis and thus overtreatment of low-risk or indolent cancers. By visualizing PCa suspicious lesions and sampling them during the targeted biopsy, it is likely that the diagnostic accuracy of significant PCa improves. This article reviews the current imaging techniques used to secure biopsies in patients with a suspicion of PCa. The advantages and limitations of each technique are described. Expert opinion: Multiparametric magnetic resonance imaging (mpMRI) and subsequent-targeted biopsy have improved the diagnostic accuracy of PCa detection in men with an elevated or rising serum PSA. Prostate lesions visible on mpMRI are easily targeted during either in-bore MRI-guided biopsy, cognitive fusion biopsy or MRI-TRUS fusion biopsy.

A randomised trial comparing two protocols for transrectal prostate repeat biopsy: six lateral posterior plus six anterior cores versus a standard posterior 12-core biopsy

Objective: To test the hypothesis that a combination of 6 posterior and 6 anterior cores detects more cancer than 12 posterior cores at a repeat transrectal prostate biopsy in men who have had one previous benign systematic biopsy.Patients and methods: Three hundred and forty men with persistently raised serum PSA were randomly allocated 1:1 to either a standard 12-core biopsy (12 cores from the lateral peripheral zone through a side-fire biopsy canal) or an experimental 12-core biopsy protocol with 6 anterior cores through an end-fire biopsy canal and 6 cores from the lateral peripheral zone through a side-fire biopsy canal. All biopsies were obtained transrectally with ultrasound guidance. The primary endpoint was cancer detection. Secondary endpoints were detection of ISUP Grade Groups/Gleason Grade Group ≥2 cancer, total biopsy cancer length and complications leading to medical intervention.Results: Prostate cancer was detected in 42/168 men (25%) in the experimental biopsy group and in 36/172 (21%) in the standard biopsy group (p = 0.44). The corresponding proportions for Gleason score ≥7 were 12% and 7% (p = 0.14). Median total cancer length was 4 (inter quartile range [IQR] = 1.5 - 6) mm in the end-fire group and 3 (IQR = 1.3 - 7) mm in the side-fire group. Ten men in the end-fire group and three in the side-fire group had a medical intervention for biopsy-related complications (p = 0.05).Conclusion: The biopsy protocol that included six end-fire anterior cores did not detect more cancer and was associated with more complications.Trial registration: ClinicalTrials.gov identifier: NCT02761135.

Performance of systematic, MRI-targeted biopsies alone or in combination for the prediction of unfavourable disease in MRI-positive low-risk prostate cancer patients eligible for active surveillance

PURPOSE

To assess the upstaging/upgrading rates of low-risk prostate cancer (PCa) according to the biopsy scheme used (systematic (SB), targeted biopsies (TB), or both) in the setting of positive pre-biopsy MRI.

PATIENTS AND METHODS

We included 143 consecutive men fulfilling the Toronto University active surveillance (AS) criteria who underwent a pre-biopsy positive MRI, a combination of SB and software-based fusion TB, and a radical prostatectomy, in two expert centres. The primary endpoints were the pathological upgrading and upstaging rates. Overall unfavourable disease (OUD) was defined by any pT3-4 and/or pN1 and/or ≥ GG 3.

RESULTS

Using TB alone would have missed 21.7% of cancers including 16.7% of ≥ GG 3. The use of TB was significantly associated with a lower risk of ≥ Grade Group (GG) 3 disease (p < 0.006) in RP specimens. Combination of SB and TB lowered this risk by 39%, compared with TB alone. The biopsy scheme did not affect the upstaging rates which were substantial even in case of combination scheme (from 37 to 46%). OUD was detected in approximately 50% of cases. The presence of high grade on TB was the only independent predictive factor for both ≥ GG 2 (p = 0.015) and ≥ GG 3 (p = 0.023) in RP specimens.

CONCLUSIONS

High grade on TB biopsies represented the major predictor of upgrading. Combination of SB and TB better defined the sub-group of patients having the lowest risk of reclassification, compared with TB or SB alone. The risk of non-organ-confined disease remained high, and could not be accurately predicted by MRI or systematic/targeted biopsy features.

The primacy of multiparametric MRI in men with suspected prostate cancer

Background

Multiparametric MRI (mpMRI) became recognised in investigating those with suspected prostate cancer between 2010 and 2012; in the USA, the preventative task force moratorium on PSA screening was a strong catalyst. In a few short years, it has been adopted into daily urological and oncological practice. The pace of clinical uptake, born along by countless papers proclaiming high accuracy in detecting clinically significant prostate cancer, has sparked much debate about the timing of mpMRI within the traditional biopsy-driven clinical pathways. There are strongly held opposing views on using mpMRI as a triage test regarding the need for biopsy and/or guiding the biopsy pattern.

Objective

To review the evidence base and present a position paper on the role of mpMRI in the diagnosis and management of prostate cancer.

Methods

A subgroup of experts from the ESUR Prostate MRI Working Group conducted literature review and face to face and electronic exchanges to draw up a position statement.

Results

This paper considers diagnostic strategies for clinically significant prostate cancer; current national and international guidance; the impact of pre-biopsy mpMRI in detection of clinically significant and clinically insignificant neoplasms; the impact of pre-biopsy mpMRI on biopsy strategies and targeting; the notion of mpMRI within a wider risk evaluation on a patient by patient basis; the problems that beset mpMRI including inter-observer variability.

Conclusions

The paper concludes with a set of suggestions for using mpMRI to influence who to biopsy and who not to biopsy at diagnosis.

Key Points

• Adopt mpMRI as the first, and primary, investigation in the workup of men with suspected prostate cancer.

• PI-RADS assessment categories 1 and 2 have a high negative predictive value in excluding significant disease, and systematic biopsy may be postponed, especially in men with low-risk of disease following additional risk stratification.

• PI-RADS assessment category lesions 4 and 5 should be targeted; PI-RADS assessment category lesion 3 may be biopsied as a target, as part of systematic biopsies or may be observed depending on risk stratification.

Electronic supplementary material

The online version of this article (10.1007/s00330-019-06166-z) contains supplementary material, which is available to authorized users.

Supervised risk predictor of central gland lesions in prostate cancer using 1 H MR spectroscopic imaging with gradient offset-independent adiabaticity pulses

BACKGROUND

Due to the histological heterogeneity of the central gland, accurate detection of central gland prostate cancer remains a challenge.

PURPOSE

To evaluate the efficacy of in vivo 3D ¹ H MR spectroscopic imaging (3D ¹ H MRSI) with a semi-localized adiabatic selective refocusing (sLASER) sequence and gradient-modulated offset-independent adiabatic (GOIA) pulses for detection of central gland prostate cancer. Additionally four risk models were developed to differentiate 1) normal vs. cancer, 2) low- vs. high-risk cancer, 3) low- vs. intermediate-risk cancer, and 4) intermediate- vs. high-risk cancer voxels.

STUDY TYPE

Prospective.

SUBJECTS

Thirty-six patients with biopsy-proven central gland prostate cancer.

FIELD STRENGTH/SEQUENCE

3T MRI / 3D ¹ H MRSI using GOIA-sLASER.

ASSESSMENT

Cancer and normal regions of interest (ROIs) were selected by an experienced radiologist and ¹ H MRSI voxels were placed within the ROIs to calculate seven metabolite signal ratios. Voxels were split into two subsets, 80% for model training and 20% for testing.

STATISTICAL TESTS

Four support vector machine (SVM) models were built using the training dataset. The accuracy, sensitivity, and specificity for each model were calculated for the testing dataset.

RESULTS

High-quality MR spectra were obtained for the whole central gland of the prostate. The normal vs. cancer diagnostic model achieved the highest predictive performance with an accuracy, sensitivity, and specificity of 96.2%, 95.8%, and 93.1%, respectively. The accuracy, sensitivity, and specificity of the low- vs. high-risk cancer and low- vs. intermediate-risk cancer models were 82.5%, 89.2%, 70.2%, and 73.0%, 84.7%, 60.8%, respectively. The intermediate- vs. high-risk cancer model yielded an accuracy, sensitivity, and specificity lower than 55%.

DATA CONCLUSION

The GOIA-sLASER sequence with an external phased-array coil allows for fast assessment of central gland prostate cancer. The classification offers a promising diagnostic tool for discriminating normal vs. cancer, low- vs. high-risk cancer, and low- vs. intermediate-risk cancer.

LEVEL OF EVIDENCE

2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;50:1926-1936.

Clinically significant prostate cancer detection on MRI: A radiomic shape features study

PURPOSE

Prostate multiparametric MRI (mpMRI) is the imaging modality of choice for detecting clinically significant prostate cancer (csPCa). Among various parameters, lesion maximum diameter and volume are currently considered of value to increase diagnostic accuracy. Quantitative radiomics allows for the extraction of more advanced shape features. Our aim was to assess which shape features derived from MRI index lesions correlate with csPCa presence.

MATERIALS AND METHODS

We retrospectively enrolled 75 consecutive subjects, who underwent mpMRI on a 3 T scanner, divided based on MRI index lesion Gleason Score in a csPCa group (GS > 3 + 4, n = 41) and a non-csPCa one (n = 34). Ten shape features were extracted both from axial T2-weighted and ADC maps images, after lesion tridimensional segmentation. Univariable and multivariable logistic analysis were used to evaluate the relationship between shape features and csPCa. Diagnostic performance was assessed measuring the area under the curve of the receiver operating characteristic (ROC) analysis. Diagnostic accuracy, sensitivity, and specificity were determined using the best cut-off on each ROC. A P value < 0.05 was considered statistically significant.

RESULTS

Univariable analysis demonstrated that almost every shape feature was statistically significant between csPCa e non-csPCa groups. However, multivariable analysis revealed that the parameter defined as surface area to volume ratio (SAVR), especially when extracted from ADC maps is the strongest independent predictor of csPCa among tested shape features.

CONCLUSION

The radiomic shape feature SAVR, extracted from ADC maps after index lesion segmentation, appears as a promising tool for csPCa detection.

Prevalence, Predictors, and Implications for Appropriate Use of Active Surveillance Management Among Black Men Diagnosed With Low-risk Prostate Cancer

BACKGROUND

Consensus guidelines recommend that active surveillance (AS) be considered in the management of men with low-risk prostate cancer (LRPC). The objective was to evaluate the prevalence and predictors of an AS approach in black men (BM) diagnosed with LRPC after inclusion of AS in LRPC consensus guidelines.

MATERIALS AND METHODS

BM and white men (WM) diagnosed with LRPC (prostate-specific antigen ≤10 ng/mL, Gleason score [GS] ≤6, clinical stage T1-T2a) between 2010 and 2013 were identified from the National Cancer Database. Logistic regression models were used to assess the likelihood of AS over time and to examine associations between sociodemographic characteristics (SDCs) and the receipt of AS. A subanalysis was performed to assess the likelihood of GS upgrading on prostatectomy specimens for cases that received definitive treatment with radical prostatectomy.

RESULTS

Overall, 9% of BM (N=15,242) with LRPC were managed with AS. The likelihood of BM undergoing AS increased from 2010 and for all subsequent years of the study period (P<0.001). Uninsured BM were twice as likely as those with private insurance to undergo AS (odds ratio [OR]=1.97; 95% confidence interval [CI], 1.51-2.58; P<0.001). BM were less likely than WM (N=86,655) to receive AS (OR=0.82; 95% CI, 0.77-0.87; P<0.001). However, on multivariate analysis adjusted for SDCs, there was no significant difference in AS utilization between the 2 race groups. Nearly half of BM (47.5%) treated with radical prostatectomy had a postprostatectomy GS≥7, and BM were 17% more likely to experience postprostatectomy upgrading to GS≥7 when compared with WM (OR=1.17; 95% CI, 1.08-1.26; P<0.001).

CONCLUSIONS

The utilization of AS for BM with LRPC seems to be increasing, is influenced by SDCs, and may not differ from AS utilization among WM. Careful consideration of prostate biopsy technique and sampling as well as SDCs at time of treatment planning may be necessary to ensure adequate evaluation of prostatic disease and appropriate disease management for BM with LRPC.

Prostate MRI, with or without MRI-targeted biopsy, and systematic biopsy for detecting prostate cancer

BACKGROUND

Multiparametric magnetic resonance imaging (MRI), with or without MRI-targeted biopsy, is an alternative test to systematic transrectal ultrasonography-guided biopsy in men suspected of having prostate cancer. At present, evidence on which test to use is insufficient to inform detailed evidence-based decision-making.

OBJECTIVES

To determine the diagnostic accuracy of the index tests MRI only, MRI-targeted biopsy, the MRI pathway (MRI with or without MRI-targeted biopsy) and systematic biopsy as compared to template-guided biopsy as the reference standard in detecting clinically significant prostate cancer as the target condition, defined as International Society of Urological Pathology (ISUP) grade 2 or higher. Secondary target conditions were the detection of grade 1 and grade 3 or higher-grade prostate cancer, and a potential change in the number of biopsy procedures.

SEARCH METHODS

We performed a comprehensive systematic literature search up to 31 July 2018. We searched CENTRAL, MEDLINE, Embase, eight other databases and one trials register.

SELECTION CRITERIA

We considered for inclusion any cross-sectional study if it investigated one or more index tests verified by the reference standard, or if it investigated the agreement between the MRI pathway and systematic biopsy, both performed in the same men. We included only studies on men who were biopsy naïve or who previously had a negative biopsy (or a mix of both). Studies involving MRI had to report on both MRI-positive and MRI-negative men. All studies had to report on the primary target condition.

DATA COLLECTION AND ANALYSIS

Two reviewers independently extracted data and assessed the risk of bias using the QUADAS-2 tool. To estimate test accuracy, we calculated sensitivity and specificity using the bivariate model. To estimate agreement between the MRI pathway and systematic biopsy, we synthesised detection ratios by performing random-effects meta-analyses. To estimate the proportions of participants with prostate cancer detected by only one of the index tests, we used random-effects multinomial or binary logistic regression models. For the main comparisions, we assessed the certainty of evidence using GRADE.

MAIN RESULTS

The test accuracy analyses included 18 studies overall.MRI compared to template-guided biopsy: Based on a pooled sensitivity of 0.91 (95% confidence interval (CI): 0.83 to 0.95; 12 studies; low certainty of evidence) and a pooled specificity of 0.37 (95% CI: 0.29 to 0.46; 12 studies; low certainty of evidence) using a baseline prevalence of 30%, MRI may result in 273 (95% CI: 249 to 285) true positives, 441 false positives (95% CI: 378 to 497), 259 true negatives (95% CI: 203 to 322) and 27 (95% CI: 15 to 51) false negatives per 1000 men. We downgraded the certainty of evidence for study limitations and inconsistency.MRI-targeted biopsy compared to template-guided biopsy: Based on a pooled sensitivity of 0.80 (95% CI: 0.69 to 0.87; 8 studies; low certainty of evidence) and a pooled specificity of 0.94 (95% CI: 0.90 to 0.97; 8 studies; low certainty of evidence) using a baseline prevalence of 30%, MRI-targeted biopsy may result in 240 (95% CI: 207 to 261) true positives, 42 (95% CI: 21 to 70) false positives, 658 (95% CI: 630 to 679) true negatives and 60 (95% CI: 39 to 93) false negatives per 1000 men. We downgraded the certainty of evidence for study limitations and inconsistency.The MRI pathway compared to template-guided biopsy: Based on a pooled sensitivity of 0.72 (95% CI: 0.60 to 0.82; 8 studies; low certainty of evidence) and a pooled specificity of 0.96 (95% CI: 0.94 to 0.98; 8 studies; low certainty of evidence) using a baseline prevalence of 30%, the MRI pathway may result in 216 (95% CI: 180 to 246) true positives, 28 (95% CI: 14 to 42) false positives, 672 (95% CI: 658 to 686) true negatives and 84 (95% CI: 54 to 120) false negatives per 1000 men. We downgraded the certainty of evidence for study limitations, inconsistency and imprecision.Systemic biopsy compared to template-guided biopsy: Based on a pooled sensitivity of 0.63 (95% CI: 0.19 to 0.93; 4 studies; low certainty of evidence) and a pooled specificity of 1.00 (95% CI: 0.91 to 1.00; 4 studies; low certainty of evidence) using a baseline prevalence of 30%, systematic biopsy may result in 189 (95% CI: 57 to 279) true positives, 0 (95% CI: 0 to 63) false positives, 700 (95% CI: 637 to 700) true negatives and 111 (95% CI: 21 to 243) false negatives per 1000 men. We downgraded the certainty of evidence for study limitations and inconsistency.Agreement analyses: In a mixed population of both biopsy-naïve and prior-negative biopsy men comparing the MRI pathway to systematic biopsy, we found a pooled detection ratio of 1.12 (95% CI: 1.02 to 1.23; 25 studies). We found pooled detection ratios of 1.44 (95% CI 1.19 to 1.75; 10 studies) in prior-negative biopsy men and 1.05 (95% CI: 0.95 to 1.16; 20 studies) in biopsy-naïve men.

AUTHORS' CONCLUSIONS

Among the diagnostic strategies considered, the MRI pathway has the most favourable diagnostic accuracy in clinically significant prostate cancer detection. Compared to systematic biopsy, it increases the number of significant cancer detected while reducing the number of insignificant cancer diagnosed. The certainty in our findings was reduced by study limitations, specifically issues surrounding selection bias, as well as inconsistency. Based on these findings, further improvement of prostate cancer diagnostic pathways should be pursued.

Magnetic resonance imaging-transrectal ultrasound image fusion guidance of prostate biopsies: current status, challenges and future perspectives

The use of multiparametric magnetic resonance imaging (mpMRI) in prostate cancer (PCa) diagnosis is rapidly evolving to try to overcome the limitations of the current diagnostic pathway using systematic transrectal ultrasound-guided biopsies (TRUS_bx) for all men with clinical suspicion of PCa. Prostate mpMRI allows for high quality lesion detection and characterization and has been shown to improve detection of significant PCa with a more accurate Gleason score grading. Suspicious lesions can be stratified by suspicion and sampled by selective MRI-guided targeted biopsies (TBx) for improved diagnostic accuracy. Several TBx methods have been established and include MRI/TRUS image fusion biopsies (cognitive or software-assisted) and in-bore biopsies, but none have yet proven superior in clinical practice. However, while MRI in-bore biopsy is not routinely used due to its costs and limited availability, MRI/TRUS image fusion is rapidly embraced as it allows skilled urologists to perform TBx in an outpatient clinic. Furthermore, it gives the operator the advantage of adding TBx to the systematic standard biopsy scheme, which is the currently recommended approach. With the anticipated increased future use of prebiopsy mpMRI, a more widespread implementation of MRI/TRUS image fusion platforms is concurrently expected in clinical practice. Therefore, the objective of this review is to assess the current status, challenges and future perspectives of prostate MRI/TRUS image fusion biopsies.

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

PURPOSE

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSIONS

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

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Combination of 68Ga-PSMA PET/CT and Multiparametric MRI Improves the Detection of Clinically Significant Prostate Cancer: A Lesion-by-Lesion Analysis

Our purpose was to explore whether ⁶⁸Ga-PSMA PET/CT alone (PET/CT) or in combination with multiparametric MRI (PET/MRI) can improve the detection of clinically significant prostate cancer (PCa). Methods: We retrospectively enrolled 54 patients who underwent both MRI and PET/CT before radical prostatectomy. Regions of interest on MR images, PET/CT images, and pathologic images were marked. A lesion was defined as a region of interest marked on images obtained with any of the 3 modalities. All lesions were characterized using the prostate imaging reporting and data system (PI-RADS), the molecular imaging PSMA expression score, and the pathologic results and analyzed. Diagnostic performance was analyzed by receiver-operating-characteristic analysis. Specific improvement for lesions with different PI-RADS scores was analyzed using the net reclassification index (NRI). Results: In total, 90 lesions from 54 patients were analyzed, among which 66 lesions represented clinically significant PCa. Receiver-operating-characteristic analysis showed PET/MRI to perform better than MRI in detecting clinically significant PCa (change in area under the curve, 0.06; 95% confidence interval, 0.01-0.12; P < 0.05). With the calculated cutoff, PET/MRI performed significantly better than MRI (NRI, 21.9%; P < 0.01), with an improvement in sensitivity (89% vs. 76%, P < 0.01) at no sacrifice of specificity (96% vs. 88%, P > 0.05). Improvement in diagnosing clinically significant PCa occurred for lesions classified as PI-RADS 3 (NRI, 66.7%; P < 0.01). Conclusion: PET/MRI improves the detection of clinically significant PCa for PI-RADS 3 lesions.

Retrospective Study of the Significant Predictive Role of Inflammatory Degree in Initial and Repeat Prostate Biopsy Specimens for Detecting Prostate Cancer

Purpose

The purpose of this study was to determine whether histologic inflammation (HI) in initial and repeat prostate biopsy specimens was significantly associated with the detection of prostate cancer.

Materials and Methods

Between 2005 and 2017, the clinicopathological records of patients with high prostatespecific antigen (PSA) levels who underwent initial and repeat prostate biopsies were retrospectively reviewed. The presence of HI and its degree in each biopsied specimen were interpreted by one uropathologist with 20 years of experience. The association between HI and cancer diagnosis was statistically assessed, with p < 0.05 considered significant, and the cancer and non-cancer groups were compared.

Results

Among the 522 patients with a median PSA levels of 6.5 ng/dL, including 258 (49.4%) whose cancer was diagnosed following repeat biopsy, the median degrees of HI in the initial and repeat biopsies were 25.0% and 41.7%, respectively. Furthermore, 211 (40.4%) and 247 (47.3%) patients had HI (> 0%) on biopsied specimens, respectively. Comparison of the cancer and noncancer groups revealed that a greater rate of HI specimens in the initial biopsy was associated with fewer prostate cancer diagnoses following repeat biopsy (p < 0.001). Other comparisons between the cancer and non-cancer groups showed that the cancer group had a significantly higher rate of hypertension, whereas those non-cancer group had a significantly higher rate of benign prostatic hyperplasia and prostatitis (p < 0.05).

Conclusion

A finding of a lesser degree of HI in the initial and a greater degree of HI in the repeat biopsied specimens was associated with the higher probability of cancer diagnosis in patients with high PSA levels.

The Use of Magnetic Resonance Imaging in the Prostate Cancer Primary Diagnostic Pathway: Is It Ready for Primetime?

Multiparametric magnetic resonance imaging (mpMRI) has been increasingly utilized in the prostate cancer diagnostic landscape over the last five years. The majority of the literature has focused on its use in men with a previous negative biopsy. However, over time, clinicians have begun using mpMRI in the work-up of men being considered for primary biopsy and subsequently data characterizing its diagnostic performance in this setting is emerging. This review comprehensively assesses the utility of mpMRI in the primary biopsy setting.

Diagnostic accuracy of magnetic resonance-guided prostate biopsy and template-guided transperineal saturation biopsy

To compare the accuracy of magnetic resonance-guided prostate biopsy (MR-GPB) and template-guided transperineal prostate saturation biopsy (TTPSB).A total of 219 patients with elevated prostate-specific antigen, abnormal digital rectal examination or ultrasound findings were enrolled. All patients underwent multiparametric magnetic resonance image (mpMRI). Patients with a Prostate Imaging Reporting and Data System (PI-RADS) score of 3 to 5 underwent MR-GPB using 2 to 5 biopsy cores and then immediately underwent an 11-region TTPSB. Patients with a PI-RADS score of 1 to 2 underwent TTPSB alone. We compared the detection rates for any cancer, clinically significant prostate cancer (csPCA), and the spatial distribution of missed csPCA lesions.Among the 219 cases, 66 (30.1%) had a PI-RADS score of 1 to 2 on mpMRI. The detection rate of TTPSB in these patients was 9.1% (6/66). In total, detection rates for any cancer and csPCA were 48.9% (107/219) and 42.9% (94/219), respectively. Detection rates for any cancer (TTPSB 87/219, 39.7%; MR-GPB76/219, 34.7%, P = .161) and csPCA (TTPSB 76/219, 34.7%; MR-GPB 72/219, 32.9%, P = .636) did not significantly differ between the 2 groups. The csPCA lesions missed by MR-GPB were most commonly located on the left (8.5%, 8/94) and right (9.6%, 9/94) sides of the urethra.MR-GPB can reduce the rate of unnecessary prostate biopsies by approximately 30% and exhibits an efficacy comparable to TTPSB for the detection of any cancer and csPCA. Nevertheless, approximately 1/4 of csPCAs were missed by MR-GPB and were most commonly located on both sides of the urethra.

The Use of Magnetic Resonance Imaging in the Prostate Cancer Primary Diagnostic Pathway: Is It Ready for Primetime?

Multiparametric magnetic resonance imaging (mpMRI) has been increasingly utilized in the prostate cancer diagnostic landscape over the last five years. The majority of the literature has focused on its use in men with a previous negative biopsy. However, over time, clinicians have begun using mpMRI in the work-up of men being considered for primary biopsy and subsequently data characterizing its diagnostic performance in this setting is emerging. This review comprehensively assesses the utility of mpMRI in the primary biopsy setting.

Comparison of conventional transrectal ultrasound, magnetic resonance imaging, and micro-ultrasound for visualizing prostate cancer in an active surveillance population: A feasibility study

INTRODUCTION

Active surveillance monitoring of prostate cancer is unique in that most patients have low-grade disease that is not well-visualized by any common imaging technique. High-resolution (29 MHz) micro-ultrasound is a new, real-time modality that has been demonstrated to be sensitive to significant prostate cancer and effective for biopsy targeting. This study compares micro-ultrasound imaging with magnetic resonance imaging (MRI) and conventional ultrasound for visualizing prostate cancer in active surveillance.

METHODS

Nine patients on active surveillance were imaged with multiparametric (mp) MRI prior to biopsy. During the biopsy procedure, imaging and target identification was first performed using conventional ultrasound, then using micro-ultrasound. The mpMRI report was then unblinded and used to determine cognitive fusion targets. Using micro-ultrasound, biopsy samples were taken from targets in each modality, plus 12 systematic samples.

RESULTS

mpMRI and micro-ultrasound both demonstrated superior sensitivity to Gleason sum 7 or higher cancer compared to conventional ultrasound (p=0.02 McNemar's test). Micro-ultrasound detected 89% of clinically significant cancer, compared to 56% for mpMRI.

CONCLUSIONS

Micro-ultrasound may provide similar sensitivity to clinically significant prostate cancer as mpMRI and visualize all significant mpMRI targets. Unlike mpMRI, micro-ultrasound is performed in the office, in real-time during the biopsy procedure, and so is expected to maintain the cost-effectiveness of conventional ultrasound. Larger studies are needed before these results may be applied in a clinical setting.