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Background: To make magnetic resonance imaging (MRI) more accessible to men at risk of high-grade prostate cancer (PCa), there is a need for quicker, simpler, and less costly MRI protocols., Objective: To compare the diagnostic performance of monoplanar ("fast" biparametric MRI [bp-MRI]) and triplanar noncontrast bp-MRI with that of the current contrast-enhanced multiparametric MRI (mp-MRI) in the detection of high-grade PCa in biopsy-naïve men., Design, Setting, and Participants: A prospective, multireader, head-to-head study included 626 biopsy-naïve men, between February 2015 and February 2018., Intervention: Men underwent prebiopsy contrast-enhanced mp-MRI. Prior to biopsy, two blinded expert readers subsequently assessed "fast" bp-MRI, bp-MRI, and mp-MRI. Thereafter, systematic transrectal ultrasound-guided biopsies (SBs) were performed. Men with suspicious mp-MRI (Prostate Imaging Reporting and Data System 3-5 lesions) also underwent MR-in-bore biopsy (MRGB)., Outcome Measurements and Statistical Analysis: Primary outcome was the diagnostic performance of each protocol for the detection of high-grade PCa. Secondary outcomes included the difference in biopsy avoidance, detection of low-grade PCa, acquisition times, decision curve analyses, inter-reader agreement, and direct costs. Results from combined MRGB and SB were used as the reference standard. High-grade PCa was defined as grade ≥2., Results and Limitations: Sensitivity for high-grade PCa for all protocols was 95% (180/190; 95% confidence interval [CI]: 91-97%). Specificity was 65% (285/436; 95% CI: 61-70%) for "fast" bp-MRI and 69% (299/436; 95% CI: 64-73%) for bp-MRI and mp-MRI. With fast bp-MRI, 0.96% (6/626) more low-grade PCa was detected. Biopsy could be avoided in 47% for the fast bp-MRI and in 49% for the bp-MRI and mp-MRI protocols. Fast bp-MRI and bp-MRI can be performed in 8 and 13min, respectively, instead of 16min at lower direct costs. Inter-reader agreement was 90% for fast bp-MRI protocol and 93% for bp-MRI protocol. A main limitation is the generalizability of these results in less experienced centers., Conclusions: Short MRI protocols can improve prostate MRI accessibility at a lower direct cost. For fast bp-MRI, this is at the cost of ∼2% more biopsies and ∼1% more overdetection of low-grade PCa. In order to implement this technique in nonexpert, low-volume, lower-field-strength scanners, further prospective studies have to be performed., Patient Summary: We compared the value of three different magnetic resonance imaging (MRI) protocols for the detection of prostate cancer in men with elevated prostate-specific antigen levels. Our results show that, when used in expert centers, shorter MRI protocols do not compromise the detection of harmful disease. This increases MRI capacity at lower direct costs., (Copyright © 2019 The Authors. Published by Elsevier B.V. All rights reserved.)

The Prostate Imaging Reporting and Data System version 2 (PI-RADS v2) was developed with a consensus-based process using a combination of published data, and expert observations and opinions. In the short time since its release, numerous studies have validated the value of PI-RADS v2 but, as expected, have also identified a number of ambiguities and limitations, some of which have been documented in the literature with potential solutions offered. To address these issues, the PI-RADS Steering Committee, again using a consensus-based process, has recommended several modifications to PI-RADS v2, maintaining the framework of assigning scores to individual sequences and using these scores to derive an overall assessment category. This updated version, described in this article, is termed PI-RADS v2.1. It is anticipated that the adoption of these PI-RADS v2.1 modifications will improve inter-reader variability and simplify PI-RADS assessment of prostate magnetic resonance imaging even further. Research on the value and limitations on all components of PI-RADS v2.1 is strongly encouraged., (Published by Elsevier B.V.)

Objective: To develop and externally validate a predictive model for detection of significant prostate cancer., Patients and Methods: Development of the model was based on a prospective cohort including 393 men who underwent multiparametric magnetic resonance imaging (mpMRI) before biopsy. External validity of the model was then examined retrospectively in 198 men from a separate institution whom underwent mpMRI followed by biopsy for abnormal prostate-specific antigen (PSA) level or digital rectal examination (DRE). A model was developed with age, PSA level, DRE, prostate volume, previous biopsy, and Prostate Imaging Reporting and Data System (PIRADS) score, as predictors for significant prostate cancer (Gleason 7 with >5% grade 4, ≥20% cores positive or ≥7 mm of cancer in any core). Probability was studied via logistic regression. Discriminatory performance was quantified by concordance statistics and internally validated with bootstrap resampling., Results: In all, 393 men had complete data and 149 (37.9%) had significant prostate cancer. While the variable model had good accuracy in predicting significant prostate cancer, area under the curve (AUC) of 0.80, the advanced model (incorporating mpMRI) had a significantly higher AUC of 0.88 (P < 0.001). The model was well calibrated in internal and external validation. Decision analysis showed that use of the advanced model in practice would improve biopsy outcome predictions. Clinical application of the model would reduce 28% of biopsies, whilst missing 2.6% significant prostate cancer., Conclusions: Individualised risk assessment of significant prostate cancer using a predictive model that incorporates mpMRI PIRADS score and clinical data allows a considerable reduction in unnecessary biopsies and reduction of the risk of over-detection of insignificant prostate cancer at the cost of a very small increase in the number of significant cancers missed., (© 2017 The Authors BJU International © 2017 BJU International Published by John Wiley & Sons Ltd.)

Objectives: To assess the image quality of T2-weighted (T2w) magnetic resonance imaging of the prostate and the visibility of prostate cancer at 7 Tesla (T)., Materials & Methods: Seventeen prostate cancer patients underwent T2w imaging at 7T with only an external transmit/receive array coil. Three radiologists independently scored images for image quality, visibility of anatomical structures, and presence of artefacts. Krippendorff's alpha and weighted kappa statistics were used to assess inter-observer agreement. Visibility of prostate cancer lesions was assessed by directly linking the T2w images to the confirmed location of prostate cancer on histopathology., Results: T2w imaging at 7T was achievable with 'satisfactory' (3/5) to 'good' (4/5) quality. Visibility of anatomical structures was predominantly scored as 'satisfactory' (3/5) and 'good' (4/5). If artefacts were present, they were mostly motion artefacts and, to a lesser extent, aliasing artefacts and noise. Krippendorff's analysis revealed an α = 0.44 between three readers for the overall image quality scores. Clinically significant cancer lesions in both peripheral zone and transition zone were visible at 7T., Conclusion: T2w imaging with satisfactory to good quality can be routinely acquired, and cancer lesions were visible in patients with prostate cancer at 7T using only an external transmit/receive body array coil., Key Points: • Satisfactory to good T2-weighted image quality of the prostate is achievable at 7T. • Periprostatic lipids appear hypo-intense compared to healthy peripheral zone tissue at 7T. • Prostate cancer is visible on T2-weighted MRI at 7T.

What's known on the subject? and What does the study add? Focal therapy techniques are emerging in prostate cancer treatment. However, several key questions about patient selection, treatment and monitoring still have to be addressed. The concept of focal therapy is barely discussed in current urological guidelines. In the present manuscript, we report the results of a consensus meeting focused on ultrasonography, the most common used urological imaging method, in relation to focal therapy of prostate cancer. • To establish a consensus on the utility of ultrasonography (US) to select patients for focal therapy. Topics were the current status of US to determine focality of prostate cancer, to monitor and assess outcome of focal therapy and the diagnostic advantages of new US methods. In addition, the biopsy techniques required to identify focal lesions were discussed. • Urological surgeons, radiation oncologists, radiologists, and basic researchers from Europe and North America participated in a consensus meeting on the use of transrectal US (TRUS) in focal therapy of prostate cancer. The consensus process was face-to-face and specific clinical issues were raised and discussed with agreement sought when possible. • TRUS is commonly used and essential for diagnosing men with prostate cancer. It is particularly useful for targeting specific anatomical regions or visible lesions. However, it has several limitations and there is a need for improvement. Newer visualisation techniques, e.g. colour Doppler US, contrast-enhanced US and elastography, are being developed but currently there is no US technique that can accurately characterise a cancer suitable for focal therapy. Systematic biopsy is the only known procedure that allows the identification of prostate cancers suitable for focal therapy. Scarce data exist about the role of US for monitoring patients during or after ablative therapy. • Consensus was reached on all key aspects of the meeting. • US cannot reliably identify focal prostate cancer. New US methods show promising results in identifying prostate cancer focality. • Currently selecting appropriate candidates for focal therapy should be performed using dedicated protocols and biopsy schemes., (© 2012 THE AUTHORS. BJU INTERNATIONAL © 2012 BJU INTERNATIONAL.)

The reported incidence of prostate cancer has risen since the implementation of screening. It is felt that the introduction of widespread prostate-specific antigen testing is responsible for most patients with prostate cancer now being diagnosed with asymptomatic, clinically localised disease. Diagnosis at this stage is associated with significantly improved treatment outcomes and longer life expectancy. Although there is evidence that screening has reduced prostate cancer mortality, there is a risk of over-diagnosis and over-treatment of early state prostate cancers, including clinically insignificant and indolent cancers. Active surveillance and focal therapy have been advocated as potential management options for some patients. However, these approaches face several challenges. Biopsy sampling errors together with less than optimal imaging of tumours can lead to difficulties in selecting suitable low-risk patients for these options.  To overcome these challenges, novel approaches to the staging and monitoring of patients with early prostate cancer are being developed. These include new imaging techniques, such as multi-parametric magnetic resonance imaging, and the development of new biomarkers and biopsy-based methods. These techniques aim to assess the potential of a specific tumour to be aggressive, and to improve patient outcomes. The aim of the present paper is to summarise presentations and debates at the third annual Interactive Genitourinary Cancer Conference concerning the use of population-based screening methods and the roles of active surveillance and focal therapy as prostate cancer treatments. The application of novel imaging biopsy-based methods and biomarkers in early-stage prostate cancer will also be explored., (© 2012 THE AUTHORS. BJU INTERNATIONAL © 2012 BJU INTERNATIONAL.)

Objectives: A prospective multicenter validation of the ability of 1H magnetic resonance spectroscopic imaging (MRSI) to distinguish cancer from noncancer tissues throughout the prostate with histopathology of the resected organ as the standard of reference., Materials and Methods: Institutional review board approval was obtained for all centers and all participating patients and volunteers provided written informed consent. Ninety-nine patients and 10 age-matched volunteers from 8 participating centers underwent magnetic resonance imaging and 3-dimensional MRSI with an endorectal coil at 1.5 T. Selected MRSI voxels were assigned to the peripheral zone (PZ), the central gland (CG), the periurethral area, and cancer tissue. Signal ratios of choline + creatine to citrate (CC/C) in spectra of these voxels were automatically calculated. Receiver operating characteristic curves were constructed to assess the accuracy by which this ratio can discriminate cancer from noncancer tissue., Results: A total of 70% of voxels in noncancer tissue and 90% of voxels in cancer tissue passed the quality check of the automatically fitted spectra. The median CC/C was significantly different between any noncancer and cancer tissue (P < 0.0001), but not between the different contributing centers. CC/C increased with cancer focus size (P =0.0008) and certainty of voxel mapping to histopathologic cancer site (P 0.0001). The area under the receiver operating characteristic curve for discriminating voxels of cancer tissue from noncancer tissue was 0.88 (confidence interval: 0.84-0.92) in the PZ and 0.76 (confidence interval: 0.71- 0.81) in the CG.

Purpose: To establish a consensus in relation to case selection, conduct of therapy, and outcomes that are associated with focal therapy for men with localized prostate cancer., Material and Methods: Urologic surgeons, radiation oncologists, radiologists, and histopathologists from North America and Europe participated in a consensus workshop on focal therapy for prostate cancer. The consensus process was face to face within a structured meeting, in which pertinent clinical issues were raised, discussed, and agreement sought. Where no agreement was possible, this was acknowledged, and the nature of the disagreement noted., Results: Candidates for focal treatment should have unilateral low- to intermediate-risk disease with clinical stage

The aim of this study was to determine which morphological features of low-intensity lesions in the peripheral zone of the prostate are predictable of prostate cancer on pre-biopsy T2-weighted integrated endorectal phased-array MR images. The MR examinations were performed in 69 consecutive patients with elevated level of prostate-specific antigen (>4 ng/ml) and/or a positive digital rectal examination before transperineal 12-site biopsy. Two radiologists evaluated presence of lesions, their morphological features, and possibility of malignancy in divided into four sections of the peripheral zone. Imaging analysis findings were compared with biopsy results. Discriminative features were selected by stepwise logistic regression. Descriptive statistics and receiver operating characteristics (ROC) curves were also calculated. Sixty-eight benign lesions and 23 malignant lesions were found. Wedge shape and diffuse extensions without mass effect were significantly associated with benignity ( P=0.0105 and 0.002, respectively). Lesion size was significantly associated with malignancy ( P=0.0001). For evaluating probability of malignancy for lesions, regression model showed a comparable accuracy with the total impression for the readers in ROC analysis (Az 0.9095 vs 0.9266, respectively). Wedge shape, diffuse extension without mass effect, and size are the morphological features of low-intensity lesions in the peripheral zone on pre-biopsy T2-weighted MR images that give the best prediction of malignancy.

The authors investigated the feasibility of a multisection proton magnetic resonance (MR) spectroscopic imaging technique for the acquisition of metabolic information in the human prostate. Multisection MR spectroscopic imaging was performed of a citrate phantom and of the prostates of eight adult volunteers. High-quality proton MR spectra and citrate metabolite maps of the prostate were obtained with this method.

Prostate and urinary bladder cancer are the most frequently encountered malignancies of the urinary tract. Appropriate use of the different imaging techniques is crucial for accurate assessment of prognosis and for the development of appropriate treatment planning. Especially determination of local tumor extension and detection of nodal or bone metastases is extremely important. In this regard MR imaging is the most promising imaging technique. Therefore, in this review its role in staging these malignancies is evaluated and compared with clinical staging, and other imaging techniques. Finally, future developments, such as new sequences, new contrast agents, the role of surface coils and MR-guided biopsy, are considered. Also, the preferred radiological approach is discussed.

Purpose: To assess whether a TurboFLASH (fast low-angle shot) magnetic resonance (MR) sequence can improve the accuracy of fast spin-echo (SE) endorectal coil MR imaging in the staging and localization of prostate cancer., Materials and Methods: In 57 patients with prostate cancer, MR imaging was performed with the following sequences: T1-weighted SE, T2-weighted fast SE, single-section gadolinium-enhanced dynamic subtracted TurboFLASH (one image every 1.25 or 2.5 seconds), and late-phase gadolinium-enhanced T1-weighted SE. Retrospectively, two blinded independent readers graded onset and steepest slope of enhancement and assessed tumor involvement and capsular penetration. MR findings were correlated with histopathologic results., Results: On TurboFLASH images, prostate cancer was characterized by early and rapidly accelerating enhancement compared with that of surrounding tissues. Average sensitivity, specificity, and accuracy for detection of tumor involvement for the two readers with TurboFLASH images were 73.5%, 81.0%, and 77.5%. These values with fast SE images were 57.5%, 80.5%, and 72.0%. Depiction of capsular penetration and delineation and staging of tumor were better when TurboFLASH images were included with fast SE images. Differences between the two sequences, however, were not statistically significant., Conclusion: Because the TurboFLASH sequence did not statistically significantly improve tumor localization and staging results, routine use is not recommended. The technique may be useful for selected patients with equivocal evidence of capsular penetration.

This report describes the use of an endorectal coil and a double spin-echo pulse sequence for localized 1H MR spectroscopy of the normal prostate in volunteers. The spectra showed well-resolved signals for citrate, (phospho)choline, and creatine protons. Additional signals were assigned to taurine and myoinositol protons. J modulation of the main and outer peaks of citrate could be monitored in vivo. Apparent relaxation times T1 and T2 have been estimated for the methyl protons of cholines and creatine. An effective T1 relaxation time was estimated for the main peaks of the citrate multiplet. Ratios of the integrals of these resonances have been evaluated, and tissue contents of choline and creatine were estimated using the H2O signal as an internal reference. Spectroscopic imaging experiments revealed a lower relative citrate signal in central parts of the prostate than in peripheral parts.

As prostate cancer is a biologically heterogeneous disease for which a variety of treatment options are available, the major objective of prostate cancer imaging is to achieve more precise disease characterization. Magnetic resonance imaging (MRI) may enhance the staging of prostate cancer compared with clinical evaluation, transrectal ultrasound, or computed tomography (CT), and allows concurrent evaluation of prostatic, periprostatic, and pelvic anatomy. In clinical practice, the fusion of MRI or dynamic contrast-enhanced MRI (DCE-MRI) with MR spectroscopic imaging (MRSI) is improving the evaluation of cancer location, size, and extent, while providing an indication of tumor aggressiveness. Pretreatment knowledge of these prognostic variables is essential for achieving minimally invasive, patient-specific therapy. [ABSTRACT FROM AUTHOR]