The accuracy of multiparametric MRI in men with negative biopsy and elevated PSA level--can it rule out clinically significant prostate cancer?

Serum PSA-based early detection of prostate cancer in Europe and globally: past, present and future

In the pre-PSA-detection era, a large proportion of men were diagnosed with metastatic prostate cancer and died of the disease; after the introduction of the serum PSA test, randomized controlled prostate cancer screening trials in the USA and Europe were conducted to assess the effect of PSA screening on prostate cancer mortality. Contradictory outcomes of the trials and the accompanying overdiagnosis resulted in recommendations against prostate cancer screening by organizations such as the United States Preventive Services Task Force. These recommendations were followed by a decline in PSA testing and a rise in late-stage diagnosis and prostate cancer mortality. Re-evaluation of the randomized trials, which accounted for contamination, showed that PSA-based screening does indeed reduce prostate cancer mortality; however, the debate about whether to screen or not to screen continues because of the considerable overdiagnosis that occurs using PSA-based screening. Meanwhile, awareness among the population of prostate cancer as a potentially lethal disease stimulates opportunistic screening practices that further increase overdiagnosis without the benefit of mortality reduction. However, in the past decade, new screening tools have been developed that make the classic PSA-only-based screening an outdated strategy. With improved use of PSA, in combination with age, prostate volume and with the application of prostate cancer risk calculators, a risk-adapted strategy enables improved stratification of men with prostate cancer and avoidance of unnecessary diagnostic procedures. This combination used with advanced detection techniques (such as MRI and targeted biopsy), can reduce overdiagnosis. Moreover, new biomarkers are becoming available and will enable further improvements in risk stratification.

Frozen section utilization to omit systematic biopsy in diagnosing high risk prostate cancer

The current guidelines for targeted prostate biopsy recommend an additional systematic biopsy regardless of clinical risk assessment. To evaluate frozen section biopsy utilization in targeted prostate biopsy to omit systematic biopsies in cases of positive frozen section results of patients with clinical features suggestive of high-risk prostate cancer. In this prospective, single-center study, we enrolled patients with a Prostate Imaging-Reporting and Data System (PI-RADS) 5 lesion on magnetic resonance imaging (MRI) with clinical evidence suggestive of high-risk prostate cancer (either an extracapsular extension or prostate-specific antigen level > 20 ng/ml). All patients underwent 2–4 core targeted biopsies utilizing frozen section biopsy with immediate results, allowing patients with a positive result to omit a systematic biopsy. In case of a negative result, additional systematic biopsies were performed. The primary endpoint was the detection rate of targeted biopsy. Patient demographics, clinical variables were analyzed using SPSS version 20. Sixty-six patients were enrolled in this study. Among them, 63 patients were diagnosed with cancer without the need for an additional systematic biopsy. Three patients were non-diagnostic with target biopsy alone. Hence an additional systematic biopsy was performed. Two of these patients were diagnosed with prostate cancer and one tested negative for cancer. In this report we looked into the necessity of taking a routine systematic biopsy in patients with high risk features of prostate cancer. We found that utilizing frozen section biopsy for targeted biopsy reduces unneccessary systematic biopsy in 97% of cases and still provides a means for systematic biopsy when targeted biopsy alone fails to make the diagnosis.

A protocol for the VISION study: An indiVidual patient data meta-analysis of randomised trials comparing MRI-targeted biopsy to standard transrectal ultraSound guided bIopsy in the detection of prOstate cancer

Background

Transrectal ultrasound (TRUS) guided biopsy for prostate cancer is prone to random and systemic error and has been shown to have a negative predictive value of 70%. PRECISION and PRECISE are among the first randomised studies to evaluate the new MRI-targeted biopsy (MRI-TB) pathway with a non-paired design to detect clinically significant prostate cancer and avoid unnecessary treatment. The trials’ results individually demonstrated non-inferiority of MRI-TB compared to TRUS biopsy. An individual patient data (IPD) meta-analysis was planned from the outset of the two trials in parallel and this IPD meta-analysis aims to further elucidate the utility of MRI-TB as the optimal diagnostic pathway for prostate cancer.

Methods and materials

This study is registered on PROSPERO (CRD42021249263). A search of Medline, Embase, Cochrane Central Register of Registered Trials (CENTRAL), Web of Science, and ClinicalTrials.gov was performed up until 4^th February 2021. Only randomised controlled trials (PRECISE, PRECISION and other eligible trials) comparing the MRI-targeted biopsy pathway and traditional TRUS biopsy pathway will be included. The primary outcome of the review is the proportion of men diagnosed with clinically significant prostate cancer in each arm (Gleason ≥ 3+4 = 7). IPD and study-level data and characteristics will be sought from eligible studies. Analyses will be done primarily using an intention-to-treat approach, and a one-step IPD meta-analysis will be performed using generalised linear mixed models. A non-inferiority margin of 5 percentage points will be used. Heterogeneity will be quantified using the variance parameters from the mixed model. If there is sufficient data, we will investigate heterogeneity by exploring the effect of the different conducts of MRIs, learning curves of MRI reporting and MRI targeted biopsies.

Trial registration

This systematic review is registered on PROSPERO (CRD42021249263)

Focal Prostate Stereotactic Body Radiation Therapy With Correlative Pathological and Radiographic-Based Treatment Planning

Introduction

Advances in multiparametric MRI (mpMRI) combining anatomic and functional imaging can accurately identify foci of adenocarcinoma within the prostate, offering the possibility of partial gland therapy. We performed tandem prospective pilot trials to investigate the feasibility of focal prostate SBRT (f-SBRT) based on correlating diagnostic mpMRI and biopsies with confirmatory pathology in treatment planning.

Materials and Methods

Patients with pathologic focal Gleason 6–7 disease and a corresponding PIRADS 4–5 lesion on mpMRI underwent targeted and comprehensive biopsies using MRI/ultrasound fusion under electromagnetic sensor navigation. After rigorous analysis for imaging biopsy concordance, five of 18 patients were eligible to proceed to f-SBRT. Chi-squared test was used for differences from expected outcomes, and concordance was estimated with binomial distribution theory and Wilson’s method.

Results

Six patients had Gleason 6 and 12 had Gleason 3 + 4 disease (mean PSA: 5.8 ng/ml, range: 2.2–8.4). Absolute concordance was 43.8% (95% CI: 0.20, 0.64). Patterns of discordance included additional sites of ipsilateral disease, bilateral disease, and negative target. Five were upstaged to a new NCCN risk category necessitating treatment escalation. The five patients with concordant pathology completed three-fraction f-SBRT with sparing of the surrounding normal structures (including contralateral neurovascular bundle), with no reported grade 2+ toxicities and favorable PSA responses (mean: 41% decrease).

Conclusions

On our pilot trials of f-SBRT planning using rigorous imaging and pathology concordance, image-guided confirmatory biopsies frequently revealed additional disease, suggesting the need for caution in partial-gland therapy. For truly focal disease, f-SBRT provided excellent dosimetry, minimal toxicity, and encouraging biochemical response. Clinical Trial Registration: www.clinicaltrials.gov, NCT02681614; NCT02163317.

MRI and Targeted Biopsy Essential Tools for an Accurate Diagnosis and Treatment Decision Making in Prostate Cancer

Prostate cancer (PCa) is one of the most frequent causes of cancer death worldwide. Historically, diagnosis was based on physical examination, transrectal (TRUS) images, and TRUS biopsy resulting in overdiagnosis and overtreatment. Recently magnetic resonance imaging (MRI) has been identified as an evolving tool in terms of diagnosis, staging, treatment decision, and follow-up. In this review we provide the key studies and concepts of MRI as a promising tool in the diagnosis and management of prostate cancer in the general population and in challenging scenarios, such as anteriorly located lesions, enlarged prostates determining extracapsular extension and seminal vesicle invasion, and prior negative biopsy and the future role of MRI in association with artificial intelligence (AI).

Multiparametric Magnetic Resonance Imaging in the Diagnosis of Clinically Significant Prostate Cancer: an Updated Systematic Review

There has been growing utilisation of multiparametric magnetic resonance imaging (MPMRI) as a non-invasive tool to diagnose and localise clinically significant prostate cancer (CSPCa). This updated systematic review examines the use of MPMRI in patients with an elevated risk of CSPCa who have had a prior negative transrectal ultrasound systematic biopsy (TRUS-SB) and who were biopsy naïve. MEDLINE, EMBASE and the Cochrane Database of Systematic Reviews were searched for existing systematic reviews published up to September 2020. The literature search of the electronic databases combined disease-specific terms (prostate cancer, prostate carcinoma, etc.) and treatment-specific terms (magnetic resonance, etc.). Studies were included if they were randomised controlled trials (RCTs) comparing MPMRI to template transperineal mapping biopsy (TPMB) or to TRUS-SB. Thirty-six RCTs were eligible. For biopsy-naïve men, accuracy of diagnosis of CSPCa showed sensitivities from 87 to 96% and specificities ranging from 29 to 45%. Meta-analyses for CSPCa showed increased detection favouring MPMRI-targeted biopsy over TRUS-SB by 3% (95% confidence interval 0-7%, P = 0.03) and decreased detection of clinically insignificant prostate cancer (CISPCa) favouring MPMRI by 8% (95% confidence interval -11 to 5%, P < 0.00001). Accuracy of MPMRI for men with prior negative biopsy showed sensitivities of 78-100% and specificities of 30-100%. Meta-analyses comparing MPMRI to TRUS-SB showed increased detection of 5% (95% confidence interval 3-7%, P < 0.0001) with a reduction of CISPCa detection of 7% (95% confidence interval 4-9%, P < 0.00001). The growing acceptance of MPMRI utilisation internationally and the recent publication of several RCTs regarding MPMRI in reducing CISPCa detection rates, particularly in biopsy-naïve men, without loss of sensitivity for CSPCa necessitates the synthesis of updated evidence examining MPMRI in the diagnosis of CSPCa.

Which Prostate Cancers are Undetected by Multiparametric Magnetic Resonance Imaging in Men with Previous Prostate Biopsy? An Analysis from the PICTURE Study

BACKGROUND

Multiparametric magnetic resonance imaging (mpMRI) has improved risk stratification for suspected prostate cancer in patients following prior biopsy. However, not all significant cancers are detected by mpMRI. The PICTURE study provides the ideal opportunity to investigate cancer undetected by mpMRI owing to the use of 5 mm transperineal template mapping (TTPM) biopsy.

OBJECTIVE

To summarise attributes of cancers systematically undetected by mpMRI in patients with prior biopsy.

DESIGN SETTING AND PARTICIPANTS

PICTURE was a paired-cohort confirmatory study in which men requiring repeat biopsy underwent mpMRI followed by TTPM biopsy.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Attributes were compared between cancers detected and undetected by mpMRI at the patient level. Four predefined histopathological thresholds were used as the target condition for TTPM biopsy. Application of prostate-specific antigen density (PSAD) was explored.

RESULTS AND LIMITATIONS

When nonsuspicious mpMRI was defined as Likert score 1-2, 2.9% of patients (3/103; 95% confidence interval [CI] 0.6-8.3%) with definition 1 disease (Gleason ≥ 4 + 3 of any length or maximum cancer core length [MCCL] ≥ 6 mm of any grade) had their cancer not detected by mpMRI. This proportion was 6.5% (11/168; 95% CI 3.3-11%) for definition 2 disease (Gleason ≥ 3 + 4 of any length or MCCL ≥ 4 mm of any grade), 4.8% (7/146; 95% CI 2.0-9.6%) for any amount of Gleason ≥ 3 + 4 cancer, and 9.3% (20/215; 95% CI 5.8-14%) for any cancer. Definition 1 cancers undetected by mpMRI had lower overall Gleason score (p = 0.02) and maximum Gleason score (p = 0.01) compared to cancers detected by mpMRI. Prostate cancers undetected by mpMRI had shorter MCCL than cancers detected by mpMRI for every cancer threshold: definition 1, 6 versus 8 mm (p = 0.02); definition 2, 5 versus 6 mm (p = 0.04); any Gleason ≥ 3 + 4, 5 versus 6 mm (p = 0.03); and any cancer, 3 versus 5 mm (p = 0.0009). A theoretical PSAD threshold of 0.15 ng/ml/ml reduced the proportion of patients with undetected disease on nonsuspicious mpMRI to 0% (0/105; 95% CI 0-3.5%) for definition 1, 0.58% (1/171; 95% CI 0.01-3.2%) for definition 2, and 0% (0/146) for any Gleason ≥ 3 + 4.

CONCLUSIONS

Few significant cancers are undetected by mpMRI in patients requiring repeat prostate biopsy. Undetected tumours are of lower overall and maximum Gleason grade and shorter cancer length compared to cancers detected by mpMRI.

PATIENT SUMMARY

In patients with a previous prostate biopsy, magnetic resonance imaging (MRI) overlooks few prostate cancers, and these tend to be smaller and less aggressive than cancer that is detected.

The utility of magnetic resonance imaging in prostate cancer diagnosis in the Australian setting

Objectives

To investigate the utility of Magnetic Resonance Imaging (MRI) for prostate cancer diagnosis in the Australian setting.

Patients and methods

All consecutive men who underwent a prostate biopsy (transperineal or transrectal) at Royal Melbourne Hospital between July 2017 to June 2019 were included, totalling 332 patients. Data were retrospectively collected from patient records. For each individual patient, the risk of prostate cancer diagnosis at biopsy based on clinical findings was determined using the European Randomized study of Screening for Prostate Cancer (ERSPC) risk calculator, with and without incorporation of MRI findings.

Results

MRI has good diagnostic accuracy for clinically significant prostate cancer. A PI‐RADS 2 or lower finding has a negative predictive value of 96% for clinically significant cancer, and a PI‐RADS 3, 4 or 5 MRI scan has a sensitivity of 93%. However, MRI has a false negative rate of 6.5% overall for clinically significant prostate cancers. Pre‐ biopsy MRI may reduce the number of unnecessary biopsies, as up to 50.0% of negative or ISUP1 biopsies have MRI PI‐RADS 2 or lower. Incorporation of MRI findings into the ERSPC calculator improved predictive performance for all prostate cancer diagnoses (AUC 0.77 vs 0.71, P = .04), but not for clinically significant cancer (AUC 0.89 vs 0.87, P = .37).

Conclusion

MRI has good sensitivity and negative predictive value for clinically significant prostate cancers. It is useful as a pre‐biopsy tool and can be used to significantly reduce the number of unnecessary prostate biopsies. However, MRI does not significantly improve risk predictions for clinically significant cancers when incorporated into the ERSPC risk calculator.

Multiparametric Magnetic Resonance Imaging in Evaluation of Clinically Significant Prostate Cancer

Aim  In this prospective study, we evaluate the role of multiparametric magnetic resonance imaging (mp-MRI) in the assessment of clinically significant prostate cancer at 1.5 T without endorectal coil (ERC).

Materials and Methods  Forty-five men with clinical suspicion of prostate cancer (prostate-specific antigen [PSA] level > 4 ng/mL, hard prostate on digital rectal examination, and suspicious area at transrectal ultrasound [TRUS]) were evaluated using the mp-MRI protocol over a period of 24 months. All cases were interpreted using the Prostate Imaging Reporting and Data System (PI-RADS) version 2 guidelines and correlated with histopathology.

Statistical Analysis Used  A chi-squared test was used for analysis of nominal/categorical variables and receiver operating characteristic (ROC) curve and one-way analysis of variance (ANOVA) test for continuous variables.

Results  The mean age was 67 years and the mean PSA was 38.2 ng/mL. Eighty percent had prostate cancer and 20% were benign (11% benign prostatic hyperplasia [BPH] and 9% chronic prostatitis). Eighty-six percent of all malignancies were in the peripheral zone. The PI-RADS score for T2-weighted (T2W) imaging showed good sensitivity (81%) but low specificity (67%). The PI-RADS score for diffusion weighted imaging (DWI) with sensitivity of 92% and specificity of 78% had a better accuracy overall than T2W imaging alone. The mean apparent diffusion coefficient (ADC) value (×10 ^–6 mm ² /s) was 732 ± 160 in prostate cancer, 1,009 ± 161 in chronic prostatitis, 1,142 ± 82 in BPH, and 663 in a single case of granulomatous prostatitis. Low ADC values (<936) have shown good correlation (area under curve [AUC]: 0.87) with the presence of cancer foci. Inverse correlation was observed between Gleason scores and ADC values. Dynamic contrast-enhanced (DCE) imaging has shown 100% sensitivity/negative predictive value (NPV), but moderate specificity (67%) in predicting malignancy. The final PI-RADS score had 100% sensitivity and NPV with good overall positive predictive value (PPV) of 95%.

Conclusions  T2W imaging and DWI remain the mainstays in diagnosis of prostate cancer with mp-MRI. DCE-MRI can be a problem-solving tool in case of equivocal findings. Because assessment with mp-MRI can be subjective, use of the newly developed PI-RADS version 2 scoring system is helpful in accurate interpretation.

Nonsuspicious prebiopsy multiparametric MRI: is prostate biopsy still necessary?

PURPOSE

To evaluate the negative predictive value (NPV) of multiparametric magnetic resonance imaging (mpMRI), alone or combined with Prostate-Specific Antigen density (PSAd) to exclude clinically significant prostate cancer (csPCa).

PATIENTS AND METHODS

We performed a retrospective chart review of all the patients who had transrectal ultrasound-guided biopsy (TRUSGB) in our center between January 2014 and March 2019. We included patients who had nonsuspicious prebiopsy mpMRI defined as Prostate Imaging-Reporting and Data System (PI-RADS) ≤ 2. MRI was performed using a 1.5 or 3-Tesla Magnetic Resonance scanners with external phased-array coil. The primary outcome was the detection of csPCa, defined as a Gleason score 3 + 4 (ISUP 2) or higher on at least one biopsy core.

RESULTS

One hundred and ninety-one consecutive men (median age: 65 years, median PSA level: 9.3 ng/mL) underwent TRUSGB following negative prebiopsy mpMRI corresponding to 126 (66%) biopsy-naïve patients, 36 (18.8%) patients with prior negative biopsy, and 29 (15.2%) patients under active surveillance with confirmatory biopsies. The overall PCa and csPCA detection rates were 26.7% and 5.2%, conferring a NPV of 73.3% and 94.8%, respectively. The NPV of negative mpMRI improved to 95.8% in patients with PSAd < 0.15 ng/mL/cm³ and to 100% in patients with PSAd < 0.10 ng/mL/cm³.

CONCLUSIONS

A negative prebiopsy mpMRI had an overall NPV of 94.8% for csPCa when mpMRI was used alone to 95.8% when combined with PSAd < 0.15 ng/mL/cm³. Future studies are needed to balance the low benefit of a biopsy in this indication with the morbidity of the procedure.

Current Role of Multiparametric MRI and MRI Targeted Biopsies for Prostate Cancer Diagnosis in Germany: A Nationwide Survey

INTRODUCTION

Multiparametric MRI (mpMRI) and MRI targeted biopsies (MRtb) are a new standard in prostate cancer (PCa) screening and diagnosis. Guidelines already include this approach for patients at risk. We aimed to gather information from German urologists about their knowledge, routine use, and attitude toward mpMRI and consecutive biopsy methods.

MATERIALS AND METHODS

An anonymous online questionnaire was sent via Survey Monkey to the members of the German Society of Urology (DGU). Statistical analyses were performed using SPSS version 25.0.

RESULTS

496 members with a median age of 48.6 years (±11.7) participated in the survey. The majority rated mpMRI of the prostate as a very useful diagnostic tool (72.7%). MRtb of the prostate was considered as very advantageous (71.5%). MpMRI was used by 95.9%, and 83.2% also recommended MRtb predominantly in clinical institutions. For targeted biopsy, MRI-ultrasound fusion biopsy was clearly favored (75.8%). MpMRI was mostly used in patients with previously negative biopsy (90.9%) and in patients under active surveillance (60.9%). Arguments against the use of prostate mpMRI are costs (84.9%) and/or lack of sufficient radiological infrastructure (17.4%).

CONCLUSION

Our data illustrate the meanwhile high acceptance and clinical use of the prostate mpMRI and MRtb in Germany.

Role of Multiparametric Magnetic Resonance Imaging in Predicting Pathologic Outcomes in Prostate Cancer

Multiparametric magnetic resonance imaging (mpMRI) and the introduction of standardized protocols for its interpretation have had a significant impact on the field of prostate cancer (PC). Multiple randomized controlled trials have shown that the sensitivity for detection of clinically significant PC is increased when mpMRI results are the basis for indication of a prostate biopsy. The added value with regards to sensitivity has been strongest for patients with persistent suspicion for PC after a prior negative biopsy. Although enhanced sensitivity of mpMRI is convincing, studies that have compared mpMRI with prostatectomy specimens prepared by whole-mount section analysis have shown a significant number of lesions that were not detected by mpMRI. In this context, the importance of an additional systematic biopsy (SB) is still being debated. While SB in combination with targeted biopsies leads to an increased detection rate, most of the tumors detected by SB only are considered clinically insignificant. Currently, multiple risk calculation tools are being developed that include not only clinical parameters but mpMRI results in addition to clinical parameters in order to improve risk stratification for PC, such as the Partin tables. In summary, mpMRI of the prostate has become a standard procedure recommended by multiple important guidelines for the diagnostic work-up of patients with suspicion of PC.

Response on DCE-MRI predicts outcome of salvage radiotherapy for local recurrence after radical prostatectomy

OBJECTIVE

To assess the predictive role of response on dynamic contrast enhancement on magnetic resonance imaging (DCE-MRI) of visible local lesions in the setting of salvage radiotherapy (sRT) after radical prostatectomy.

METHODS

All patients referred for sRT for biochemical failure after radical prostatectomy from February 2014 to September 2016 were considered eligible if they had been restaged with DCE-MRI and had been found to have a visible lesion in the prostatic bed, but no distant/nodal disease on choline positron emission tomography (PET)-computed tomography (CT). Eligible patients were contacted during follow-up and offered reimaging with serial DCE-MRI until lesion resolution. Complete response (CR) was defined as the disappearance of the target lesion on DCE-MRI; prostate-specific antigen (PSA) recurrence was defined as a 0.2 ng/mL PSA rise above the nadir. Median follow-up after sRT was 41.5 months (range, 12.1-61.2 months).

RESULTS

Fifty-nine patients agreed to undergo repeated DCE-MRI for a total of 64 studied lesions. Overall, 57 lesions (89.1%) showed a CR after 1 (51 patients) or 2 (6 patients) scans, while 7 lesions did not show any change (no response [NR]). At 42 months, no evidence of biochemical disease (bNED) survival was 74.7±6.4% and 64.3±21.0% for patients with CR and NR lesions, respectively (hazard ratio [HR], 3.181; 95% confidence interval [CI], 0.157-64.364; p = 0.451). When only patients treated with sRT without androgen deprivation were selected (n = 41), bNED survival rates at 42 months were 72.1±8.0% and 0, respectively (HR, 52.830; 95% CI, 1.893-1474.110; p = 0.020).

CONCLUSIONS

Patients whose lesions disappear during follow-up have a better outcome than those with unchanged lesions after sRT alone.

Multiparametric MRI for prostate cancer diagnosis: current status and future directions

The current diagnostic pathway for prostate cancer has resulted in overdiagnosis and consequent overtreatment as well as underdiagnosis and missed diagnoses in many men. Multiparametric MRI (mpMRI) of the prostate has been identified as a test that could mitigate these diagnostic errors. The performance of mpMRI can vary depending on the population being studied, the execution of the MRI itself, the experience of the radiologist, whether additional biomarkers are considered and whether mpMRI-targeted biopsy is carried out alone or in addition to systematic biopsy. A number of challenges to implementation remain, such as ensuring high-quality execution and reporting of mpMRI and ensuring that this diagnostic pathway is cost-effective. Nevertheless, emerging clinical trial data support the adoption of this technology as part of the standard of care for the diagnosis of prostate cancer.

The Use of Multiparametric Magnetic Resonance Imaging (mpMRI) in the Detection, Evaluation, and Surveillance of Clinically Significant Prostate Cancer (csPCa)

PURPOSE OF REVIEW

With the long-standing controversy surrounding the use of prostate-specific antigen (PSA) for the detection, evaluation, and surveillance of prostate cancer, there is a need for a minimally invasive technique to identify and risk-stratify these patients. Additionally, in an effort to reduce the number of unnecessary biopsies and identify clinically significant prostate cancer (csPCa), there has been a shift in practice towards the use of multiparametric magnetic resonance imaging (mpMRI) in conjunction with decision-making regarding prostate cancer diagnosis and management. In the current review, we summarize the data regarding the use of mpMRI in the detection, evaluation, and surveillance of csPCa.

RECENT FINDINGS

Recent prospective clinical trials have determined that a pre-biopsy mpMRI may rule out insignificant prostate cancers, thereby reducing the number of patients who require a biopsy. The anatomic information gathered from these pre-biopsy mpMRI performed during MRI fusion biopsy in csPCa increases the accuracy of pathologic staging in terms of Gleason scores. In regard to active surveillance, prospective trials suggest little to no clinical utility for mpMRI and fusion biopsy in the surveillance of prostate cancer despite conflicting findings from retrospective studies. Recent trials suggest that mpMRI can play an important role in the detection and evaluation of csPCa. The ideal role for mpMRI in active surveillance remains limited.

18F-Choline PET/mpMRI for Detection of Clinically Significant Prostate Cancer: Part 1. Improved Risk Stratification for MRI-Guided Transrectal Prostate Biopsies

A prospective single-arm clinical trial was conducted to determine whether ¹⁸F-choline PET/mpMRI can improve the specificity of multiparametric MRI (mpMRI) of the prostate for Gleason ≥ 3+4 prostate cancer. Methods: Before targeted and systematic prostate biopsy, mpMRI and ¹⁸F-choline PET/CT were performed on 56 evaluable subjects with 90 Likert score 3-5 mpMRI target lesions, using a ¹⁸F-choline target-to-background ratio of greater than 1.58 to indicate a positive ¹⁸F-choline result. Prostate biopsies were performed after registration of real-time transrectal ultrasound with T2-weighted MRI. A mixed-effects logistic regression was applied to measure the performance of mpMRI (based on prospective Likert and retrospective Prostate Imaging Reporting and Data System, version 2 [PI-RADS], scores) compared with ¹⁸F-choline PET/mpMRI to detect Gleason ≥ 3+4 cancer. Results: The per-lesion accuracy of systematic plus targeted biopsy for mpMRI alone was 67.8% (area under receiver-operating-characteristic curve [AUC], 0.73) for Likert 4-5 and 70.0% (AUC, 0.76) for PI-RADS 3-5. Several PET/MRI models incorporating ¹⁸F-choline with mpMRI data were investigated. The most promising model selected all high-risk disease on mpMRI (Likert 5 or PI-RADS 5) plus low- and intermediate-risk disease (Likert 4 or PI-RADS 3-4), with an elevated ¹⁸F-choline target-to-background ratio greater than 1.58 as positive for significant cancer. Using this approach, the accuracy on a per-lesion basis significantly improved to 88.9% for Likert (AUC, 0.90; P < 0.001) and 91.1% for PI-RADS (AUC, 0.92; P < 0.001). On a per-patient basis, the accuracy improved to 92.9% for Likert (AUC, 0.93; P < 0.001) and to 91.1% for PI-RADS (AUC, 0.91; P = 0.009). Conclusion: ¹⁸F-choline PET/mpMRI improved the identification of Gleason ≥ 3+4 prostate cancer compared with mpMRI, with the principal effect being improved risk stratification of intermediate-risk mpMRI lesions.

MRI to guide biopsies or avoid biopsies?

PURPOSE OF REVIEW

To discuss contemporary data on the value of multiparametric MRI (mpMRI) for guiding the decision to biopsy men at risk for prostate cancer, as well as its utility in active surveillance programs.

RECENT FINDINGS

Although a systematic 12-core biopsy is the current standard of care for men with increased suspicion for prostate cancer, MRI with or without targeted biopsy has been shown to reliably improve the detection of clinically significant disease following a prior negative biopsy. At the same time, there is a growing body of evidence to support the use of MRI for diagnostic purposes in biopsy-naive patients, as well for enrolling and monitoring men on active surveillance programs.

SUMMARY

mpMRI is an evolving technology with great promise for altering our approach to prostate cancer diagnosis and surveillance. In conjunction with targeted biopsies, MRI offers greater specificity for the detection of clinically significant cancer and therefore may help to reduce overdetection of indolent disease while minimizing the risks and limitations of systematic biopsies.

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.

Effect of miR-200c on proliferation, invasion and apoptosis of prostate cancer LNCaP cells

Effect of miRNA-200c (miR-200c) on the proliferation, invasion and apoptosis of prostate cancer cell line LNCaP was investigated. The difference in miR-200c expression was observed using RT-qPCR in the NC group (transfected empty plasmid), simulation group (simulation sequence) and inhibition group (transferred inhibition sequence), which were established by transfecting LNCaP cells with a kit. The proliferation, invasion and apoptosis of cells after transfection were detected using the cell counting kit-8 (CCK-8) method, Transwell chamber and flow cytometry. RT-qPCR detection showed that the relative expression of miR-200c in LNCaP cells significantly increased compared with RWPE-1 cells (P<0.05). The difference was statistically significant in the relative expression of miR-200c cells among NC group, simulation group and inhibition group after transfection (P<0.05) and they significantly decreased in NC group of cells compared with the simulation group (P<0.05). CCK-8 detection showed that there were differences at the 2nd, 3rd, 4th and 5th days of growth in the NC group, simulation group and inhibition group of cells (P<0.05) and there was a difference in the proliferation ability between NC group and simulation group (P<0.05). Transwell chamber detection showed that there was a difference in the invasion ability among NC group, simulation group and inhibition group of cells (P<0.05), among which the number of passed membrane cells in inhibition group was significantly smaller than that in NC group and simulation group (P<0.05), and the difference was not statistically significant between NC group and simulation group (P>0.05). Flow cytometry detection of the apoptosis ability of each group of cells showed that there was a difference in the apoptotic rate in the NC, simulation and inhibition groups (P<0.05). The low expression of miR-200c is beneficial to inhibit the proliferation and invasion of LNCaP cells in vitro and to promote apoptosis, which may be a potential target for prostate cancer biotherapy.

Multiparametric MRI fusion-guided prostate biopsy in biopsy naive patients: Preliminary results from 80 patients

OBJECTIVE

The aim of this prospective study was to evaluate the early results of transrectal prostate biopsies performed under the guidance of multiparametric prostate magnetic resonance imaging (mpMRI) in biopsy naive patients.

MATERIAL AND METHODS

Biopsy naive patients who had prostate-specific antigen level 4-10 ng/mL and/or abnormal digital rectal examination findings and provided informed consent were examined using mpMRI. The study included 80 patients with an MRI-defined lesion with a Prostate Imaging and Reporting and Data System (PIRADS) score of ≥3. All mpMRIs were reported by the same uro-radiologist according to PIRADS version 2. An MRI-targeted biopsy was performed by an ultrasonography system with rigid fusion registration software. The first two to five core biopsies per MRI-defined lesions were obtained, and then a standard random 12-core biopsy was performed. Transrectal biopsies were performed under local anesthesia or sedoanalgesia.

RESULTS

Of the 80 patients, 29 (36.3%) were found to have cancer using the conventional 12-core biopsy, but only 20 (25%) were found to have prostate cancer using the MRI-targeted prostate biopsy. Combining the two biopsy methods (conventional+MRI-targeted), cancer detection rate increased to 43.8% (35/80 patients). The cancer detection rate using the combined method was statistically higher than that using the conventional biopsy method (p=0.03). Using the conventional biopsy method, 960 core biopsies were collected from 80 patients. Of the 960 core biopsies, 111 (11.6%) were found to be cancer. Further, 101 suspected lesions were detected using mpMRI in 80 patients. In addition, 397 core biopsies were obtained from these lesions. Of the 397 core biopsies, 62 (15.6%) were reported as prostate cancer. The core positivity rate of MR-targeted biopsy was statistically higher than that of conventional biopsy (p=0.04).

CONCLUSION

The preliminary results of MRI-targeted prostate biopsy combined with conventional biopsy suggested that the combined biopsy method was crucial in prostate cancer diagnosis especially in patients with prostate cancer suspicion and no biopsy history. However, larger sample prospective studies are needed to validate the effectiveness of MRI-targeted biopsy and combined biopsy methods.

Population-based outcomes of men with a single negative prostate biopsy: Importance of continued follow-up among older patients

PURPOSE

To determine in Ontario-based men with a single negative transrectal ultrasound-guided prostate biopsy the long-term rates of prostate cancer-specific mortality, diagnosis, and treatment; number of repeat biopsies; and predictors of prostate cancer diagnosis and mortality.

MATERIALS AND METHODS

This was a population-based cohort study, using data from linked, validated health administrative databases, of all Ontario-based men with a negative first biopsy between January 1994 and October 2014. Patients were followed from time of first biopsy till death, administrative censoring, or end of study period. Cumulative incidence functions were used to calculate the study outcomes' cumulative incidences. Univariable and multivariable regression analyses using Fine and Gray's semiparametric proportional hazards model were used to assess predictors of prostate cancer diagnosis and mortality.

RESULTS

The study cohort included 95,675 men with a median age of 63.0years. Median follow-up was 8.1years. The 20-year cumulative rates of prostate cancer-specific mortality and diagnosis were 1.8% and 23.7%, respectively. Men ages 70 to 79 and 80 to 84 at initial biopsy had 20-year prostate cancer-specific mortality cumulative rates of 3.2% and 6.4% respectively. The 20-year cumulative rate of receiving radical prostatectomy was 7.6%. Higher socioeconomic status and urban residence were associated with higher diagnosis risks yet lower prostate cancer-specific mortality risks.

CONCLUSIONS

This is the first population-based study assessing long-term cancer outcomes in North American men with a single negative transrectal ultrasound-guided prostate biopsy. Following a negative initial biopsy, 23.7% of men are still diagnosed with and 1.8% die of prostate cancer within 20years. Cancer-specific mortality outcomes are significantly worse in older men, with prostate cancer mortality rates several times higher than the rest of the population.

MpMRI of the prostate: is there a role for semi-quantitative analysis of DCE-MRI and late gadolinium enhancement in the characterisation of prostate cancer?

AIM

To assess whether there is a significant difference in perfusion parameters between benign and malignant prostatic lesions, focusing on semi-quantitative analysis of dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) and presence of late gadolinium enhancement (LGE).

MATERIAL AND METHODS

Three hundred and thirteen patients who underwent multiparametric MRI (mpMRI) of the prostate and with available corresponding histology (prostatectomy or biopsy) were selected retrospectively for this study. The MRI protocol consisted of multiplanar T2-and diffusion-weighted imaging, DCE and delayed axial T1 images. Images were reviewed independently by two radiologists for LGE assessment and Prostate Imaging - Reporting and Data System (PI-RADS) scoring. For each lesion, semi-quantitative analysis of DCE-MRI was performed and the following data were evaluated: time to peak, wash-in rate, wash-out rate, brevity of enhancement, and area under the curve. The presence or absence of LGE in delayed axial T1 images was assessed qualitatively. MRI results were compared to histology. The presence of significant prostate cancer was based both on Epstein criteria (SPC) and Gleason score (GS ≥7).

RESULTS

SPC and Gleason score ≥7 tumours showed significant lower time to peak and brevity of enhancement (p<0.001) with higher wash-in rate (p=0.001). LGE was observed in 152/313 (49%) cases; among them 103/152 (68%) did not show SPC whereas 49/152 (32%) had SPC (p<0.001). The presence of LGE determined a risk reduction of SPC resulting as an independent predictor at multivariate analysis (logOR=-0.78, SE 0.33, p=0.02).

CONCLUSION

Semi-quantitative perfusion analysis and LGE may help to predict the presence/absence of a significant prostate tumour and represent a promising tool to improve mpMRI diagnostic performance.

Effectiveness of the «cognitive» biopsy in the diagnosis of prostate cancer in patients with a previous negative biopsy

INTRODUCTION

Evaluation of the effectiveness of cognitive biopsy (CB) in patients with clinical suspicion of prostate cancer (PC), and at least one negative biopsy (TRB).

MATERIAL AND METHOD

Retrospective study of 144 patients with at least one previous TRB and magnetic resonance imaging (MRI). The MRI nodules were classified based on PI-RADS v2 grouping pZa, pZpl and pZpm as the peripheral zone(PZ), Tza, Tzp and CZ as the transitional zone (TZ), and the AS zones as the anterior zone (AZ). A biopsy was indicated for nodules ≥PI-RADS 3. Uni and multivariate analysis was undertaken (logistic regression) to identify variables relating to a PI-RADS 3 tumour on biopsy.

RESULTS

The median age was 67 (IQR: 62-72) years, the median PSA was 8.2 (IQR: 6.2-12) ng/ml. A nodule was identified on MRI in the PZ in 97 (67.4%) cases, in the TZ in 29 (20.1%), and in the AZ in 41 (28.5%). PC was diagnosed on biopsy in 64 (44%) patients. The cancer rate in the PI-RADS 3 lesions was 17.5% (7/40), in the PI-RADS 4 47.3% (35/73), and in the PI-RADS 5 lesions it was 73.3% (22/29) (p=.0001). Multivariable analysis with variables that could influence the biopsy result in patients with PI-RADS 3: None (age, PSA, number of previous biopsies, rectal examination, PSAD, prostate volume or number of extracted cylinders) behaved as an independent tumour predictor.

CONCLUSIONS

The diagnostic performance of CB in patients with at least one previous negative biopsy was 44%, increasing according to the PI-RADS grade, and low in PI-RADS 3. No clinical variable predictive of cancer was found in patients with PI-RADS 3.

Diagnostic Accuracy of a Rapid Biparametric MRI Protocol for Detection of Histologically Proven Prostate Cancer

OBJECTIVE

To evaluate the performance of a rapid, low cost, noncontrast MRI examination as a secondary screening tool in detection of clinically significant prostate cancer.

METHODS

In this prospective single institution study, 129 patients with elevated prostate-specific antigen levels or abnormal digital rectal examination findings underwent MRI with an abbreviated biparamatric MRI protocol consisting of high-resolution axial T2- and diffusion-weighted images. Index lesions were classified according to modified Prostate Imaging - Reporting and Data System (mPI-RADS) version 2.0. All patients underwent standard transrectal ultrasound-guided biopsy after MRI with the urologist being blinded to MRI results. Subsequently, all patients with suspicious lesions (mPI-RADS 3, 4, or 5) underwent cognitively guided targeted biopsy after discussion of MRI results with the urologist. Sensitivity and negative predictive value for identification of clinically significant prostate cancer (Gleason score 3+4 and above) were determined.

RESULTS

Rapid biparametric MRI discovered 176 lesions identified in 129 patients. Rapid MRI detected clinically significant cancers with a sensitivity of 95.1% with a negative predictive value of 95.1% and positive predictive value of 53.2%, leading to a change in management in 10.8% of the patients. False negative rate of biparametric (bp) MRI was 4.7%.

CONCLUSION

We found that a bp-MRI examination can detect clinically significant lesions and changed patient management in 10.8% of the patients. A rapid MRI protocol can be used as a useful secondary screening tool in men presenting with suspicion of prostate cancer.

Risk of upgrading from prostate biopsy to radical prostatectomy pathology: Is magnetic resonance imaging-guided biopsy more accurate?

Background: This study compared magnetic resonance imaging-guided biopsy (MRI-GB) and transrectal ultrasound guided biopsy (TRUS-GB) with the final histology of the radical prostatectomy (RP) specimen.

Methods: Our subjects were 229 patients with prostate cancer (PCa), proven histopathologically using MRI-GB or TRUS-GB, who underwent RP at our center between December 2015 and December 2016. The main group included 92 patients who underwent MRI-GB and the control group included 137 patients who underwent 12-core TRUS-GB. Histological findings for RP specimens were compared with those from biopsies. We also evaluated predictors of upgraded Gleason score (GS), using uni- and multivariate analyses.

Results: Upgraded GS between biopsy and RP specimen occurred to 22.7% (52/229) of the cohort overall. In univariate analysis, prostate-specific antigen density (PSAD) (P<0.001), prostate volume (PV) < 30 ml (P<0.001), biopsy modality (P=0.027), biopsy GS (P=0.032) and measured MRI lymph node metastasis (P=0.018) were prognostic factors. Multivariate logistic regression analysis showed PV < 30 ml (P<0.001) and biopsy modality (P=0.001) were independent predictors of upgraded GS.

Conclusions: MRI-GB may enhance the diagnostic accuracy of prostate cancer detection in final histopathology with lower rate of upgraded GS than TRUS-GB. Also, PV < 30 ml and biopsy modality were independent predictors of upgraded GS.

Accuracy of tumor segmentation from multi-parametric prostate MRI and 18F-choline PET/CT for focal prostate cancer therapy applications

BACKGROUND

The study aims to assess the accuracy of multi-parametric prostate MRI (mpMRI) and 18F-choline PET/CT in tumor segmentation for clinically significant prostate cancer. 18F-choline PET/CT and 3 T mpMRI were performed in 10 prospective subjects prior to prostatectomy. All subjects had a single biopsy-confirmed focus of Gleason ≥ 3+4 cancer. Two radiologists (readers 1 and 2) determined tumor boundaries based on in vivo mpMRI sequences, with clinical and pathologic data available. 18F-choline PET data were co-registered to T2-weighted 3D sequences and a semi-automatic segmentation routine was used to define tumor volumes. Registration of whole-mount surgical pathology to in vivo imaging was conducted utilizing two ex vivo prostate specimen MRIs, followed by gross sectioning of the specimens within a custom-made 3D-printed plastic mold. Overlap and similarity coefficients of manual segmentations (seg1, seg2) and 18F-choline-based segmented lesions (seg3) were compared to the pathologic reference standard.

RESULTS

All segmentation methods greatly underestimated the true tumor volumes. Human readers (seg1, seg2) and the PET-based segmentation (seg3) underestimated an average of 79, 80, and 58% of the tumor volumes, respectively. Combining segmentation volumes (union of seg1, seg2, seg3 = seg4) decreased the mean underestimated tumor volume to 42% of the true tumor volume. When using the combined segmentation with 5 mm contour expansion, the mean underestimated tumor volume was significantly reduced to 0.03 ± 0.05 mL (2.04 ± 2.84%). Substantial safety margins up to 11-15 mm were needed to include all tumors when the initial segmentation boundaries were drawn by human readers or the semi-automated 18F-choline segmentation tool. Combining MR-based human segmentations with the metabolic information based on 18F-choline PET reduced the necessary safety margin to a maximum of 9 mm to cover all tumors entirely.

CONCLUSIONS

To improve the outcome of focal therapies for significant prostate cancer, it is imperative to recognize the full extent of the underestimation of tumor volumes by mpMRI. Combining metabolic information from 18F-choline with MRI-based segmentation can improve tumor coverage. However, this approach requires confirmation in further clinical studies.

New prostate cancer prognostic grade group (PGG): Can multiparametric MRI (mpMRI) accurately separate patients with low-, intermediate-, and high-grade cancer?

PURPOSE

Our objective is to determine the accuracy of multiparametric MRI (mpMRI) in predicting pathologic grade of prostate cancer (PCa) after radical prostatectomy (RP) using simple apparent diffusion coefficient metrics and, specifically, whether mpMRI can accurately separate disease into one of two risk categories (low vs. higher grade) or one of three risk categories (low, intermediate, or high grade) corresponding to the new prognostic grade group (PGG) criteria.

METHODS

This retrospective, HIPAA-compliant, IRB-approved study included 140 patients with PCa who underwent 3 T mpMRI with endorectal coil and transrectal ultrasound-guided (TRUS-G) biopsy before RP. MpMRI was used to classify lesions using a two-tier (low-grade/PGG 1 vs. high-grade/PGG 2-5) or a three-tier system (low-grade/PGG 1 vs. intermediate-grade/PGG 2 vs. high-grade/PGG 3-5). Accuracy of mpMRI was compared against RP for each system.

RESULTS

The predictive accuracy of mpMRI using the two-tier system is higher than when using three-tier system (0.77 and 0.45, respectively). There were similar rates of undergrading between mpMRI and TRUS-G biopsy compared to RP (16% & 21%; respectively); rate of overgrading was higher for mpMRI vs. TRUS-G biopsy compared to RP (42% & 17%, respectively). When mpMRI and TRUS-G biopsy are combined, rate of undergrading is 1.4% and overgrading is 11%.

CONCLUSIONS

MpMRI predictive accuracy is higher when using a two-tier vs. a three-tier system, suggesting that advanced metrics may be necessary to delineate intermediate- from high-grade disease. Rates of under- and overgrading decreased when mpMRI and TRUS-G biopsy are combined, suggesting that these techniques may be complementary in predicting tumor grade.

[Prostate cancer diagnostic by saturation randomized biopsy versus rigid targeted biopsy]

INTRODUCTION

Optimal diagram teaming up randomized biopsy (BR) to targeted biopsy (BC) is still missing for the diagnostic of prostate cancer (CP). This study compares diagram of 6, 12 or 18 BR with or without BC rigid.

METHODS

Between January 2014 and May 2016, 120 patients had prostate biopsy BR and BC. Each patient had 18 BR and BC. Results compared sextant (6 BR), standard (12 BR) and saturation (18 BR) protocol with or without the adding of BC for the detection of CP.

RESULTS

Rectal examination was normal, mean PSA at 8.99ng/mL and mean volume at 54cm³. It was first round for 48% of patients. Forty-four cancers were found by the group 18 BR+BC (control). The detection rate was respectively, for 6, 12 and 18 BR of 61%, 82% and 91%. The add of BC increased this detection of +27% for 6 BR+BC, +13% for 12 BR+BC and +9% for 18 BR+BC. BC found 70% of all CP. Nine percent of CP were missed by BR only. Significant CP (Gleason≥7) diagnostic was the same for 12 BR+BC and 18 BR+BC.

CONCLUSION

The add of BC to BR increase the detection of CP by 10%. Twelve BR+BC is the optimal diagram for the diagnostic of CP finding 95% of CP and 97% of significant CP.

LEVEL OF EVIDENCE

4.

A systematic review on multiparametric MR imaging in prostate cancer detection

BACKGROUND

Literature data suggest that multi-parametric Magnetic Resonance Imaging (MRI), including morphologic T2-weigthed images (T2-MRI) and functional approaches such as Dynamic Contrast Enhanced-MRI (DCE-MRI), Diffusion Weighted Imaging (DWI) and Magnetic Resonance Spectroscopic Imaging (MRSI), give an added value in the prostate cancer localization and local staging.

METHODS

We performed a systematic review of literature about the role and the potentiality of morphological and functional MRI in prostate cancer, also in a multimodal / multiparametric approach, and we reported the diagnostic accuracy results for different imaging modalities and for different MR coil settings: endorectal coil (ERC) and phased array coil (PAC). Forest plots and receiver operating characteristic curves were performed. Risk of bias and the applicability at study level were calculated.

RESULTS

Thirty three papers were identified for the systematic review. Sensitivity and specificity values were, respectively, for T2-MRI of 75% and of 60%, for DCE-MRI of 80% and of 72%, for MRSI of 89% and of 69%, for combined T2-MRI and DCE-MRI of 87% and of 46%, for combined T2-MRI and MRSI of 79% and of 57%, for combined T2-MRI, DWI and DCE-MRI of 81% and of 84%, and for combined MRSI and DCE-MRI of 83% and of 83%. For MRI studies performed with ERC we obtained a pooled sensitivity and specificity of 81% and of 66% while the pooled values for MRI studies performed with PAC were of 78% and of 64%, respectively (p>0.05 at McNemar test). No studies were excluded from the analysis based on the quality assessment.

CONCLUSIONS

ERC use yielded no additional benefit in terms of prostate cancer detection accuracy compared to multi-channel PAC use (71% versus 68%) while the use of additional functional imaging techniques (DCE-MRI, DWI and MRSI) in a multiparametric MRI protocol improves the accuracy of prostate cancer detection allowing both the early cure and the guidance of biopsy.

What Are We Missing? False-Negative Cancers at Multiparametric MR Imaging of the Prostate

Purpose To characterize clinically important prostate cancers missed at multiparametric (MP) magnetic resonance (MR) imaging. Materials and Methods The local institutional review board approved this HIPAA-compliant retrospective single-center study, which included 100 consecutive patients who had undergone MP MR imaging and subsequent radical prostatectomy. A genitourinary pathologist blinded to MP MR findings outlined prostate cancers on whole-mount pathology slices. Two readers correlated mapped lesions with reports of prospectively read MP MR images. Readers were blinded to histopathology results during prospective reading. At histopathologic examination, 80 clinically unimportant lesions (<5 mm; Gleason score, 3+3) were excluded. The same two readers, who were not blinded to histopathologic findings, retrospectively reviewed cancers missed at MP MR imaging and assigned a Prostate Imaging Reporting and Data System (PI-RADS) version 2 score to better understand false-negative lesion characteristics. Descriptive statistics were used to define patient characteristics, including age, prostate-specific antigen (PSA) level, PSA density, race, digital rectal examination results, and biopsy results before MR imaging. Student t test was used to determine any demographic differences between patients with false-negative MP MR imaging findings and those with correct prospective identification of all lesions. Results Of the 162 lesions, 136 (84%) were correctly identified with MP MR imaging. Size of eight lesions was underestimated. Among the 26 (16%) lesions missed at MP MR imaging, Gleason score was 3+4 in 17 (65%), 4+3 in one (4%), 4+4 in seven (27%), and 4+5 in one (4%). Retrospective PI-RADS version 2 scores were assigned (PI-RADS 1, n = 8; PI-RADS 2, n = 7; PI-RADS 3, n = 6; and PI-RADS 4, n = 5). On a per-patient basis, MP MR imaging depicted clinically important prostate cancer in 99 of 100 patients. At least one clinically important tumor was missed in 26 (26%) patients, and lesion size was underestimated in eight (8%). Conclusion Clinically important lesions can be missed or their size can be underestimated at MP MR imaging. Of missed lesions, 58% were not seen or were characterized as benign findings at second-look analysis. Recognition of the limitations of MP MR imaging is important, and new approaches to reduce this false-negative rate are needed. ^© RSNA, 2017 Online supplemental material is available for this article.

Accuracy of dynamic contrast-enhanced magnetic resonance imaging in the diagnosis of prostate cancer: systematic review and meta-analysis

The goals of this meta-analysis were to assess the effectiveness of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in patients with prostate carcinoma (PCa) and to explore the risk profiles with the highest benefit. Systematic electronic searched were conducted in database. We used patient-based and biopsy-based pooled weighted estimates of the sensitivity, specificity, and a summary receiver operating characteristic (SROC) curve for assessing the diagnostic performance of DCE. We performed direct and indirect comparisons of DCE and other methods of imaging. A total of 26 articles met the inclusion criteria for the analysis. DCE-MRI pooled sensitivity was 0.53 (95% CI 0.39 to 0.67), with a specificity of 0.88 (95% CI 0.83 to 0.92) on whole gland. The peripheral zone pooled sensitivity was 0.70 (95% CI 0.46 to 0.86), with a specificity of 0.88 (95% CI 0.76 to 0.94). Compared with T2-weighted imaging (T2WI), DCE was statistically superior to T2. In conclusion, DCE had relatively high specificity in detecting PCa but relatively low sensitivity as a complementary functional method. DCE-MRI might help clinicians exclude cases of normal tissue and serve as an adjunct to conventional imaging when seeking to identify tumor foci in patients with PCa.

Magnetic Resonance Spectroscopy and its Clinical Applications: A Review

In vivo NMR spectroscopy is known as magnetic resonance spectroscopy (MRS). MRS has been applied as both a research and a clinical tool in order to detect visible or nonvisible abnormalities. The adaptability of MRS allows a technique that can probe a wide variety of metabolic uses across different tissues. Although MRS is mostly applied for brain tissue, it can be used for detection, localization, staging, tumour aggressiveness evaluation, and tumour response assessment of breast, prostate, hepatic, and other cancers. In this article, the medical applications of MRS in the brain, including tumours, neural and psychiatric disorder studies, breast, prostate, hepatic, gastrointestinal, and genitourinary investigations have been reviewed.

Score 3 prostate lesions: a gray zone for PI-RADS v2

Prostate Imaging Reporting and Data System version 2 (PI-RADS v2) does not offer a precise guidance on the clinical management (biopsy or not biopsy) for PI-RADS v2 score 3 lesions. Lesion volume calculated on biparametric MRI (bpMRI) [T2-weighted imaging (T2WI) and diffusion-weighted imaging (DWI)] by introducing a cut-off of 0.5 mL, allows to distinguish the lesions assigned by the multiparametric MRI (mpMRI) to the category PI-RADS v2 score 3 in two subgroups: a) Indolent or low risk lesions with volume <0.5 mL, and b) Significant or high risk lesions with volume ≥0.5 mL. For mpMRI lesions assigned to PI-RADS v2 score 3, we suggest the following management: 1) Subgroup a (low-risk lesion): Clinical surveillance (accurate evaluation of age and clinical informations, periodic monitoring of prostate specific antigen value and repeated bpMRI 1 year later); 2) Subgroup b (high-risk lesion): Targeted biopsy. The proposed management would reduce the use of unnecessary biopsies and increase the diagostic yield of significant prostate cancer of approximately 50% and 30% respectively. These approaches encourage the radiologist to adopt MRI lesion volume to improve PI-RADS v2 and to optimize the management of PI-RADS v2 score 3 lesions.

Magnetic resonance imaging detection of prostate cancer in men with previous negative prostate biopsy

Use of transrectal ultrasound guided systematic prostate biopsy has poor diagnostic accuracy for prostate cancer (PCa) detection. Recently multiparametric MRI (mpMRI) of the prostate and MR/US fusion biopsy has been gaining popularity for men who have previously undergone a negative biopsy. We performed PubMed® and Web of Science® searches to identify studies on this subject, particularly focusing on studies consisting of patients who have had at least one previously negative biopsy. Across the literature, when a suspicious lesion is found on mpMRI, MR/US fusion biopsy has consistently demonstrated higher detection rate for any PCa and clinically significant PCa (csPCa) compared to the traditional repeat systematic biopsy (SB) approach. Furthermore, anteriorly located tumors are frequently identified using MR targeted biopsy (TB), suggesting that an MR guided approach allows for increased accuracy for detecting tumors commonly missed by systematic biopsies. We conclude that men with a prior negative biopsy and continued suspicion of PCa should strongly be encouraged to get a prostate mpMRI prior to a repeat biopsy.

Diagnostic value of MRI-based PSA density in predicting transperineal sector-guided prostate biopsy outcomes

PURPOSE

Prostate-specific antigen (PSA) density (PSAD) has potential to increase the diagnostic utility of PSA, yet has had poor uptake in clinical practice. We aimed to determine the diagnostic value of magnetic resonance imaging-derived PSAD (MR-PSAD) in predicting transperineal sector-guided prostate biopsy (TPSB) outcomes.

MATERIALS AND METHODS

Men presenting for primary TPSB from 2007 to 2014 were considered. Histological outcomes were assessed and defined as: presence of any cancer or significant cancer defined as presence of Gleason 4 and/or maximum tumour core length (MCCL) ≥ 4 mm (G4); or Gleason 4 and/or MCCL ≥ 6 mm (G6). Sensitivity, specificity and positive and negative predictive values were calculated, and receiver operating characteristics (ROC) curves were generated to compare MR-PSAD and PSA.

RESULTS

Six hundred fifty-nine men were evaluated with mean age 62.5 ± 9 years, median PSA 6.7 ng/ml (range 0.5-40.0), prostate volume 40 cc (range 7-187) and MR-PSAD 0.15 ng/ml/cc (range 0.019-1.3). ROC area under the curve (95% CI) was significantly better for MR-PSAD than PSA for all cancer definitions (p < 0.001): 0.73 (0.70-0.76) versus 0.61 (0.57-0.64) for any cancer; 0.75 (0.71-0.78) versus 0.66 (0.62-0.69) for G4; and 0.77 (0.74-0.80) versus 0.68 (0.64-0.71) for G6. Sensitivities for MR-PSAD < 0.1 ng/ml/cc were 85.0, 89.9 and 91.9% for any, G4 and G6 cancer, respectively.

CONCLUSION

MR-PSAD may be better than total PSA in determining risk of positive biopsy outcome. Its use may improve risk stratification and reduce unnecessary biopsies.

Role of Imaging in the Era of Precision Medicine

Precision medicine is an emerging approach for treating medical disorders, which takes into account individual variability in genetic and environmental factors. Preventive or therapeutic interventions can then be directed to those who will benefit most from targeted interventions, thereby maximizing benefits and minimizing costs and complications. Precision medicine is gaining increasing recognition by clinicians, healthcare systems, pharmaceutical companies, patients, and the government. Imaging plays a critical role in precision medicine including screening, early diagnosis, guiding treatment, evaluating response to therapy, and assessing likelihood of disease recurrence. The Association of University Radiologists Radiology Research Alliance Precision Imaging Task Force convened to explore the current and future role of imaging in the era of precision medicine and summarized its finding in this article. We review the increasingly important role of imaging in various oncological and non-oncological disorders. We also highlight the challenges for radiology in the era of precision medicine.

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

CONTEXT

It remains unclear whether patients with a suspicion of prostate cancer (PCa) and negative multiparametric magnetic resonance imaging (mpMRI) can safely obviate prostate biopsy.

OBJECTIVE

To systematically review the literature assessing the negative predictive value (NPV) of mpMRI in patients with a suspicion of PCa.

EVIDENCE ACQUISITION

The Embase, Medline, and Cochrane databases were searched up to February 2016. Studies reporting prebiopsy mpMRI results using transrectal or transperineal biopsy as a reference standard were included. We further selected for meta-analysis studies with at least 10-core biopsies as the reference standard, mpMRI comprising at least T2-weighted and diffusion-weighted imaging, positive mpMRI defined as a Prostate Imaging Reporting Data System/Likert score of ≥3/5 or ≥4/5, and results reported at patient level for the detection of overall PCa or clinically significant PCa (csPCa) defined as Gleason ≥7 cancer.

EVIDENCE SYNTHESIS

A total of 48 studies (9613 patients) were eligible for inclusion. At patient level, the median prevalence was 50.4% (interquartile range [IQR], 36.4-57.7%) for overall cancer and 32.9% (IQR, 28.1-37.2%) for csPCa. The median mpMRI NPV was 82.4% (IQR, 69.0-92.4%) for overall cancer and 88.1% (IQR, 85.7-92.3) for csPCa. NPV significantly decreased when cancer prevalence increased, for overall cancer (r=-0.64, p<0.0001) and csPCa (r=-0.75, p=0.032). Eight studies fulfilled the inclusion criteria for meta-analysis. Seven reported results for overall PCa. When the overall PCa prevalence increased from 30% to 60%, the combined NPV estimates decreased from 88% (95% confidence interval [95% CI], 77-99%) to 67% (95% CI, 56-79%) for a cut-off score of 3/5. Only one study selected for meta-analysis reported results for Gleason ≥7 cancers, with a positive biopsy rate of 29.3%. The corresponding NPV for a cut-off score of ≥3/5 was 87.9%.

CONCLUSIONS

The NPV of mpMRI varied greatly depending on study design, cancer prevalence, and definitions of positive mpMRI and csPCa. As cancer prevalence was highly variable among series, risk stratification of patients should be the initial step before considering prebiopsy mpMRI and defining those in whom biopsy may be omitted when the mpMRI is negative.

PATIENT SUMMARY

This systematic review examined if multiparametric magnetic resonance imaging (MRI) scan can be used to reliably predict the absence of prostate cancer in patients suspected of having prostate cancer, thereby avoiding a prostate biopsy. The results suggest that whilst it is a promising tool, it is not accurate enough to replace prostate biopsy in such patients, mainly because its accuracy is variable and influenced by the prostate cancer risk. However, its performance can be enhanced if there were more accurate ways of determining the risk of having prostate cancer. When such tools are available, it should be possible to use an MRI scan to avoid biopsy in patients at a low risk of prostate cancer.

1.5-Tesla Multiparametric-Magnetic Resonance Imaging for the detection of clinically significant prostate cancer

BACKGROUND AND AIM

Multiparametric-magnetic resonance imaging (mp-MRI) is the main imaging modality used for prostate cancer detection. The aim of this study is to evaluate the diagnostic performance of mp-MRI at 1.5-Tesla (1.5-T) for the detection of clinically significant prostate cancer.

METHODS

In this ethical board approved prospective study, 39 patients with suspected prostate cancer were included. Patients with a history of positive prostate biopsy and patients treated for prostate cancer were excluded. All patients were examined at 1.5-T MRI, before standard transrectal ultrasonography-guided biopsy.

RESULTS

The overall sensitivity, specificity, positive predictive value and negative predictive value for mp-MRI were 100%, 73.68%, 80% and 100%, respectively.

CONCLUSION

Our results showed that 1.5 T mp-MRI has a high sensitivity for detection of clinically significant prostate cancer and high negative predictive value in order to rule out significant disease.

Risk of prostate cancer diagnosis and mortality in men with a benign initial transrectal ultrasound-guided biopsy set: a population-based study

BACKGROUND

The risk of missing prostate cancer in the transrectal ultrasound-guided systematic biopsies of the prostate in men with suspected prostate cancer is a key problem in urological oncology. Repeat biopsy or MRI-guided biopsies have been suggested to increase sensitivity for diagnosis of prostate cancer, but the risk of disease-specific mortality in men who present with raised prostate-specific antigen (PSA) concentration and a benign initial biopsy result remains unknown. We investigated the risk of overall and prostate cancer-specific mortality in men with a benign initial biopsy set.

METHODS

Data were extracted from the Danish Prostate Cancer Registry-a population-based registry including all men undergoing histopathological assessment of prostate tissue. All men who were referred for transrectal ultrasound-guided biopsy for assessment of suspected prostate cancer between Jan 1, 1995, and Dec 31, 2011, in Denmark were eligible for inclusion. Follow-up data were obtained on April 28, 2015. The primary endpoint was the cumulative incidence of prostate cancer-specific mortality, analysed in a competing risk setting, with death from other causes as the competing event.

FINDINGS

Between Jan 1, 1995, and Dec 31, 2011, 64 430 men were referred for transrectal ultrasound-guided biopsy, of whom 63 454 were eligible for inclusion. Median follow-up was 5·9 years (IQR 3·8-8·5) and the total follow-up time, from the enrolment of the first patient on Jan 1, 1995, until the extraction of causes of death on April 28, 2015, was 20 years. 10 407 (30%) of 35 159 men with malignant initial biopsy sets died from prostate cancer, compared with 541 (2%) of 27 181 men with benign initial biopsy sets. Estimated overall 20-year mortality was 76·1% (95% CI 73·0-79·2). In all men referred for transrectal ultrasound-guided biopsy, the cumulative incidence of prostate cancer-specific mortality after 20 years was 25·6% (24·7-26·5) versus 50·5% (47·5-53·5) for mortality from other causes. In men with benign initial biopsy sets, the cumulative incidence of prostate cancer-specific mortality was 5·2% (3·9-6·5) versus 59·9% (55·2-64·6) for mortality from other causes. In men with PSA concentrations 10 μg/L or lower and benign initial biopsy sets (2779 men), the cumulative incidence of prostate cancer-specific mortality was 0·7% (0·2-1·3). Cumulative incidence of prostate cancer specific mortality in men with benign initial biopsy sets was 3·6% (95% CI 0·1-7·2) for men with a PSA higher than 10 ng/mL but 20 ng/mL or less (855 men) and 17·6% (12·7-22·4) and for men with a PSA higher than 20 ng/mL (454 men).

INTERPRETATION

The first systematic transrectal ultrasound-guided biopsy set holds important prognostic information. The 20-year risk of prostate cancer-specific mortality in men with benign initial results is low. Our findings question whether men with low PSA concentration and a benign initial biopsy set should undergo further diagnostic assessment in view of the high risk of mortality from other causes.

FUNDING

Capital Region of Denmark's Fund for Health Research, Danish Cancer Society, Danish Association for Cancer Research, and Krista and Viggo Petersen's Foundation.

Everyman's prostate phantom: kiwi-fruit substitute for human prostates at magnetic resonance imaging, diffusion-weighted imaging and magnetic resonance spectroscopy

OBJECTIVES

To apply an easy-to-assemble phantom substitute for human prostates in T2-weighted magnetic resonance imaging (T2WI), diffusion-weighted imaging (DWI) and 3D magnetic resonance spectroscopy (MRS).

METHODS

Kiwi fruit were fixed with gel hot and cold compress packs on two plastic nursery pots, separated by a plastic plate, and submerged in tap water inside a 1-L open-spout plastic watering can for T2WI (TR/TE 7500/101 ms), DWI (5500/61 ms, ADC b50-800 s/mm² map) and MRS (940/145 ms) at 3.0 T, with phased array surface coils. One green kiwi fruit was additionally examined with an endorectal coil. Retrospective comparison with benign peripheral zone (PZ) and transitional zone (TZ) of prostate (n = 5), Gleason 6-7a prostate cancer (n = 8) and Gleason 7b-9 prostate cancer (n = 7) validated the phantom.

RESULTS

Mean contrast between central placenta (CP) and outer pericarp (OP, 0.346-0.349) or peripheral placenta (PP, 0.364-0.393) of kiwi fruit was similar to Gleason 7b-9 prostate cancer and PZ (0.308) in T2WI. ADC values of OP and PP (1.27 ± 0.07-1.37 ± 0.08 mm²/s × 10^-3) resembled PZ and TZ (1.39 ± 0.17-1.60 ± 0.24 mm²/s × 10^-3), while CP (0.91 ± 0.14-0.99 ± 0.10 mm²/s × 10^-3) resembled Gleason 7b-9 prostate cancer (1.00 ± 0.25 mm²/s × 10^-3). MR spectra showed peaks of citrate and myo-inositol in kiwi fruit, and citrate and "choline+creatine" in prostates. The phantom worked with an endorectal coil, too.

CONCLUSIONS

The kiwi fruit phantom reproducibly showed zones similar to PZ, TZ and cancer in human prostates in T2WI and DWI and two metabolite peaks in MRS and appears suitable to compare different MR protocols, coil systems and scanners.

KEY POINTS

• Kiwi fruit appear suitable as phantoms for human prostate in MR examinations. • Kiwi fruit show zonal anatomy like human prostates in T2-weighted MRI and DWI. • MR spectroscopy reliably shows peaks in kiwi fruit (citrate/inositol) and human prostates (citrate/choline+creatine). • The kiwi fruit phantom works both with and without an endorectal coil. • EU regulation No. 543/2011 specifies physical and biochemical properties of kiwi fruit.