Evaluating Biparametric Versus Multiparametric Magnetic Resonance Imaging for Diagnosing Clinically Significant Prostate Cancer: An International, Paired, Noninferiority, Confirmatory Observer Study.

BACKGROUND AND OBJECTIVE: Biparametric magnetic resonance imaging (bpMRI), excluding dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI), is a potential replacement for multiparametric MRI (mpMRI) in diagnosing clinically significant prostate cancer (csPCa). An extensive international multireader multicase observer study was conducted to assess the noninferiority of bpMRI to mpMRI in csPCa diagnosis. METHODS: An observer study was conducted with 400 mpMRI examinations from four European centers, excluding examinations with prior prostate treatment or csPCa (Gleason grade [GG] ≥2) findings. Readers assessed bpMRI and mpMRI sequentially, assigning lesion-specific Prostate Imaging Reporting and Data System (PI-RADS) scores (3-5) and a patient-level suspicion score (0-100). The noninferiority of patient-level bpMRI versus mpMRI csPCa diagnosis was evaluated using the area under the receiver operating curve (AUROC) alongside the sensitivity and specificity at PI-RADS ≥3 with a 5% margin. The secondary outcomes included insignificant prostate cancer (GG1) diagnosis, diagnostic evaluations at alternative risk thresholds, decision curve analyses (DCAs), and subgroup analyses considering reader expertise. Histopathology and ≥3 yr of follow-up were used for the reference standard. KEY FINDINGS AND LIMITATIONS: Sixty-two readers (45 centers and 20 countries) participated. The prevalence of csPCa was 33% (133/400); bpMRI and mpMRI showed similar AUROC values of 0.853 (95% confidence interval [CI], 0.819-0.887) and 0.859 (95% CI, 0.826-0.893), respectively, with a noninferior difference of -0.6% (95% CI, -1.2% to 0.1%, p < 0.001). At PI-RADS ≥3, bpMRI and mpMRI had sensitivities of 88.6% (95% CI, 84.8-92.3%) and 89.4% (95% CI, 85.8-93.1%), respectively, with a noninferior difference of -0.9% (95% CI, -1.7% to 0.0%, p < 0.001), and specificities of 58.6% (95% CI, 52.3-63.1%) and 57.7% (95% CI, 52.3-63.1%), respectively, with a noninferior difference of 0.9% (95% CI, 0.0-1.8%, p < 0.001). At alternative risk thresholds, mpMRI increased sensitivity at the expense of reduced specificity. DCA demonstrated the highest net benefit for an mpMRI pathway in cancer-averse scenarios, whereas a bpMRI pathway showed greater benefit for biopsy-averse scenarios. A subgroup analysis indicated limited additional benefit of DCE MRI for nonexperts. Limitations included that biopsies were conducted based on mpMRI imaging, and reading was performed in a sequential order. CONCLUSIONS AND CLINICAL IMPLICATIONS: It has been found that bpMRI is noninferior to mpMRI in csPCa diagnosis at AUROC, along with the sensitivity and specificity at PI-RADS ≥3, showing its value in individuals without prior csPCa findings and prostate treatment. Additional randomized prospective studies are required to investigate the generalizability of outcomes.

Radiogenomics Map-Based Molecular and Imaging Phenotypical Characterization in Localised Prostate Cancer Using Pre-Biopsy Biparametric MR Imaging.

To create a radiogenomics map and evaluate the correlation between molecular and imaging phenotypes in localized prostate cancer (PCa), using radical prostatectomy histopathology as a reference standard. Radiomic features were extracted from T2-weighted (T2WI) and Apparent Diffusion Coefficient (ADC) images of clinically localized PCa patients (n = 15) across different Gleason score-based risk categories. DNA extraction was performed on formalin-fixed, paraffin-embedded (FFPE) samples. Gene expression analysis of androgen receptor expression, apoptosis, and hypoxia was conducted using the Chromosome Analysis Suite (ChAS) application and OSCHIP files. The relationship between gene expression alterations and textural features was assessed using Pearson's correlation analysis. Receiver operating characteristic (ROC) analysis was utilized to evaluate the predictive accuracy of the model. A significant correlation was observed between radiomic texture features and copy number variation (CNV) of genes associated with apoptosis, hypoxia, and androgen receptor (p-value ≤ 0.05). The identified radiomic features, including Sum Entropy ADC, Inverse Difference ADC, Sum Variance T2WI, Entropy T2WI, Difference Variance T2WI, and Angular Secondary Moment T2WI, exhibited potential for predicting cancer grade and biological processes such as apoptosis and hypoxia. Incorporating radiomics and genomics into a prediction model significantly improved the prediction of prostate cancer grade (clinically significant prostate cancer), yielding an AUC of 0.95. Radiomic texture features significantly correlate with genotypes for apoptosis, hypoxia, and androgen receptor expression in localised prostate cancer. Integration of these into the prediction model improved prediction accuracy of clinically significant prostate cancer.

Discrepancy in the Location of Prostate Cancer Indicated on Biparametric Magnetic Resonance Imaging and Pathologically Diagnosed Using Surgical Specimens.

Accurate diagnosis of the localization of prostate cancer (PCa) on magnetic resonance imaging (MRI) remains a challenge. We aimed to assess discrepancy between the location of PCa pathologically diagnosed using surgical specimens and lesions indicated as possible PCa by the Prostate Imaging Reporting and Data System on MRI. The primary endpoint was the concordance rate between the site of probable clinically significant PCa (csPCa) identified using biparametric MRI (bpMRI) and location of PCa in the surgical specimen obtained using robot-assisted total prostatectomy. Among 85 lesions identified in 30 patients; 42 (49.4%) were identified as possible PCa on MRI. The 85 PCa lesions were divided into positive and negative groups based on the bpMRI results. None of the patients had missed csPCa. Although the diagnostic accuracy of bpMRI was relatively high for PCas located in the middle of the prostate (p = 0.029), it was relatively low for PCa located at the base of the prostate, all of which were csPCas. Although current modalities can accurately diagnose PCa, the possibility that PCa is present with multiple lesions in the prostate should be considered, even if MRI does not detect PCa.

Combination of biparametric magnetic resonance imaging with prostate-specific antigen density to stratify the risk of significant prostate cancer: Initial biopsy and long-term follow-up results.

OBJECTIVES: To assess whether the combination of biparametric magnetic resonance imaging with prostate-specific antigen density can properly stratify the risk of significant prostate cancer in patients undergoing prostate biopsies and how this approach affects the detection of prostate cancer during follow-up in patients who do not undergo prostate biopsy. METHODS: In total, 411 biopsy-naïve patients who had elevated prostate-specific antigen levels and then underwent biparametric magnetic resonance imaging for suspicious prostate cancer were analyzed: 203 patients underwent prostate biopsies, whereas 208 patients did not. Significant prostate cancer detection rates stratified by the combination of Prostate Imaging Reporting and Data System score and prostate-specific antigen density were assessed in patients who underwent prostate biopsies. The cumulative incidence of prostate cancer detection during the follow-up was assessed in patients who omitted biopsy. RESULTS: The negative predictive value for significant prostate cancer was 89% for Prostate Imaging Reporting and Data System scores 1-3, which increased to 97% when prostate-specific antigen density <0.15 ng/ml/cm3 was combined. Among patients who did not undergo biopsy, patients with Prostate Imaging Reporting and Data System scores 1-3 plus prostate-specific antigen density <0.15 ng/ml/cm3 included significantly less cases in which significant prostate cancer was detected during the follow-up, compared with the others (3.2% versus 17% at 36 months). CONCLUSIONS: Restriction of prostate biopsies to patients with Prostate Imaging Reporting and Data System scores 4-5 or prostate-specific antigen density ≥0.15 ng/ml/cm3 proved to be the good biopsy strategy, effectively balancing risks and benefits.

Predictors of upgrading from low-grade cancer at prostatectomy in men with biparametric magnetic resonance imaging.

Introduction: Prostate-specific antigen (PSA) density has previously been identified as a predictor of histological upgrading at radical prostatectomy, but how information from pre-treatment biparametric magnetic resonance imaging (bpMRI) contributes needs further clarification. The objective of this register-based study was to identify predictors of upgrading at prostatectomy in men with Grade group (GG) 1 and pre-treatment bpMRI. Material and methods: This single-center study included men with GG 1 cancer on prediagnostic biopsy, who underwent bpMRI and robotic-assisted radical prostatectomy (RARP) between March 2014 and September 2019. We estimated logistic regression models to explore predictors for upgrading. The explored potential predictors were age, PSA density, tumor stage and Prostate Imaging Reporting and Data System (PI-RADS) score (dichotomised 1-3 versus 4-5). Results: Upgrading was observed in 56% (73/130) of the men. PSA density was the only significant predictor for upgrading (unadjusted OR = 1.7, 95% CI 1.2; 2.4 adjusted OR = 1.7, 95% CI 1.2; 2.5). The probability of upgrading was lower for men with a PIRADS 1-3 than for PIRADS 4-5, but the difference was not statistically significant (adjusted OR 0.4, 95% CI 0.2; 1.1, p = 0.082). Among men with PI-RADS 1-3, the probability increased with increasing PSA density (p = 0.036). With PI-RADS 4-5 the probability of upgrading was high over the entire PSA density range. Conclusions: PSA density is a clinically important factor to predict upgrading from GG1 when bpMRI shows PI-RADS 1-3. In men with PI-RADS 4-5 on bpMRI, the probability of an undetected GG 2-5 cancer is high regardless of the PSA density.

Diagnostic accuracy and discriminative power of biparametric versus multiparametric MRI in predicting muscle-invasive bladder cancer.

PURPOSE: Investigate and compare the diagnostic accuracy and discriminative power of biparametric MRI (bp-MRI) and multiparametric MRI (mp-MRI) in predicting muscle-invasive bladder cancer (MIBC) based on Vesical Imaging-Reporting and Data System (VI-RADS) scoring and evaluate potentially influencing factors on both protocols' accuracy. METHOD: This retrospective study included 54 bladder cancer (BC) patients who underwent bladder MRI and histo-pathological assessment. Three readers independently reviewed the MRI studies and assigned a 1-5 score for T2-weighted, diffusion-weighted, and dynamic contrast-enhanced images. Then, bp-MRI and mp-MRI final VI-RADS scores were recorded for each BC. Diagnostic tables, chi-square test, kappa score (k), logistic regression, receiver operating characteristics (ROC) curves, areas under the curves (AUCs), and VI-RADS cut-off values were calculated. A Delong test was performed for ROC curve comparison. A P-value<0.05 was considered significant. RESULTS: In predicting MIBC, bp-MRI and mp-MRI had comparable diagnostic accuracy with insignificant differences for the three readers (P = 0.364,0.718,0.702). Radiologists' experience, and tumors' size and morphology had insignificant effect on bp-MRI accuracy (P = 0.086, 0.392,0.294), respectively. Tumors' size significantly influenced mp-MRI accuracy (P = 0.039). Bp-MRI and mp-MRI had comparable discriminative power with insignificant differences for all readers (P > 0.05). Using VI-RADS > 3 cut-off value improved the discriminative power of bp-MRI. Excellent inter-reader agreement in VI-RADS scoring for bp-MRI (k range, 0.814-0.867) and mp-MRI (k range, 0.787-0.859) was observed. CONCLUSION: Bp-MRI and mp-MRI demonstrated comparable diagnostic accuracy and discriminative power in predicting MIBC. The accuracy of bp-MRI was not influenced by radiologists' experience, or tumors' size and morphology.

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

Background: Only limited data have been published on the diagnostic accuracy of combining biparametric (bp) magnetic resonance imaging (MRI) and prostate-specific antigen density (PSAd) to rule out biopsies. Purpose: The purpose is to assess the 2-year risk of being diagnosed with sPCa following the strategy of avoiding immediate biopsies in men with non-suspicious bp MRIs and a PSAd <0.15 ng/mL2. Material and Methods: Two hundred biopsy-naïve men with clinical suspicion of PCa underwent a pre-biopsy bp MRI from March to July 2019. Of these, 109 men had a Prostate Imaging Reporting and Data System (PI-RADS) score of 1-3 including 77 men with calculated PSAd <0.15 ng/mL2. As a result, no biopsies were performed in these 77 men, who were clinically followed up for at least 2 years and re-examined in case of rising suspicion of sPCa. The remaining 32 men with a calculated PSAd ≥0.15 ng/mL2 underwent systematic biopsies and targeted biopsies of any PI-RADS 3 lesion. Results: One of the 77 men (1.3%) had an sPCa diagnosed within 2 years of follow-up. All men were referred back to their general practitioner within 1 year and 9% (7/77) were re-referred to the urology department during follow-up. Among these men, 43% (3/7) continued to have PSA levels that were above their individual thresholds at confirmatory testing and underwent secondary MRI scans. Conclusions: No biopsies for men with bpMRI results exhibiting maximum PI-RADS 3 and with a PSAd <0.15 ng/mL2 resulted in a 2-year risk of being diagnosed with sPCa of 1.3%.

One-Day Prostate Cancer Diagnosis: Biparametric Magnetic Resonance Imaging and Digital Pathology by Fluorescence Confocal Microscopy.

In this prospective observational study, we tested the feasibility and efficacy of a novel one-day PCa diagnosis path based on biparametric magnetic resonance (bpMRI) and digital pathology by fluorescence confocal microscopy (FCM). Patients aged 55-70 years scheduled for PBx due to increased PSA levels (3-10 ng/mL) and/or abnormal digitorectal examination were enrolled. All patients underwent bpMRI and PBx with immediate FCM evaluation of biopsy cores. Patients were asked to fill out a dedicated Patient Satisfaction Questionnaire. Patients' satisfaction rates and concordance between digital pathology and standard HE evaluation were the outcomes of interest. Twelve patients completed our one-day PCa diagnosis path. BpMRI showed suspicious lesions in 7 patients. Digital pathology by FCM identified PCa in 5 (41.7%) of the 12 patients. Standard pathology confirmed the diagnosis made through digital pathology in all the cases. At a per patient level, high concordance between the methods was achieved in Gleason Grading (4 out of 5 patients). The level of agreement in the number of positive cores was lower but did not affect the choice of treatment in any of the 5 PCa cases. At a per core level, the agreement was very high for the diagnosis of anyPCa (96.2%) and csPCa (97.3%), with a k coefficient of 0.90 and 0.92, respectively (near perfect agreement). In conclusion, one-day PCa diagnosis by FCM represents a feasible, reliable, and fast diagnostic method that provides significant advantages in optimizing time and resources, leading to patients having a higher quality standard of care perception.

bpMRI and mpMRI for detecting prostate cancer: A retrospective cohort study.

Background: We aimed to compare the detection rates of prostate cancer (PCa) and clinically significant prostate cancer(csPCa) by biparametric (bp-) and multiparameter magnetic resonance imaging (mpMRI). Materials and Methods: A total of 699 patients who underwent transperineal prostate biopsy in the Department of Urology, the Second Affiliated Hospital of Nantong University from January 2018 to December 2021 were retrospectively reviewed. Multivariate analysis was used to explore the influencing factors associated with the detection rates of PCa and csPCa. According to MRI examination before biopsy, the patients were divided into bpMRI group and mpMRI group. The detection rates of PCa and csPCa by bpMRI and mpMRI were compared. Furthermore, stratified analysis was performed for patients in these two groups to compare the detection rates of PCa and csPCa at different tPSA intervals, different prostate volume (PV) intervals and different PI-RADS V2 scores. Results: A total of 571 patients were finally analyzed in this study after exclusion, and the overall detection rate of PCa was 54.5%. Multivariate analysis showed that patient age, tPSA level, prostate volume and PI-RADS V2 score were independent risk factors affecting the detection rates of PCa and csPCa. The detection rates of PCa and csPCa by bpMRI and mpMRI were comparable (51.3% vs. 57.9%, 44.0% vs. 48.0%, both P > 0.05), with no statistical significance. In the tPSA 10-20 ng/ml interval, the detection rates of PCa (59.72% vs. 40.35%, P = 0.011) and csPCa (51.39% vs. 28.82%, P = 0.005) by mpMRI were significantly higher than those by bpMRI, while in other tPSA interval (tPSA < 4 ng/ml, 4-10 ng/ml, 20-100 ng/ml), different PVs (≤30 ml, 30-60 ml, >60 ml) and different PI-RADS V2 scores (3, 4, and 5), the detection rates of PCa and csPCa were comparable between the two groups. Conclusion: For detecting PCa and csPCa, bpMRI and mpMRI had similar diagnostic efficacies, whereas mpMRI detected more PCa and csPCa in the tPSA interval of 10-20 ng/ml.

How to read biparametric MRI in men with a clinical suspicious of prostate cancer: Pictorial review for beginners with public access to imaging, clinical and histopathological database.

Prostate Magnetic Resonance Imaging (MRI) is increasingly being used in men with a clinical suspicion of prostate cancer (PCa). Performing prostate MRI without the use of an intravenous contrast (IV) agent in men with a clinical suspicion of PCa can lead to reduced MRI scan time. Enabling a large array of different medical providers (from mid-level to specialized radiologists) to evaluate and potentially report prostate MRI in men with a clinical suspicion of PCa with a high accuracy could be one way to enable wide adoption of prostate MRI in men with a clinical suspicion of PCa. The aim of this pictorial review is to provide an insight into acquisition, quality control and reporting of prostate MRI performed without IV contrast agent in men with a clinical suspicion of PCa, aimed specifically at radiologists starting reporting prostate MRI, urologists, urology/radiology residents and mid-level medical providers without experience in reporting prostate MRI. Free public access (http://petiv.utu.fi/improd/and http://petiv.utu.fi/multiimprod/) to complete datasets of 161 and 338 men is provided. The imaging datasets are accompanied by clinical, laboratory and histopathological findings. Several topics are simplified in order to provide a solid base for the development of skills needed for an unsupervised review and potential reporting of prostate MRI in men with a clinical suspicion of PCa. The current review represents the first step towards enabling a large array of different medical providers to review and report accurately prostate MRI performed without IV contrast agent in men with a clinical suspicion of PCa.

[Clinical impact of abbreviated unenhanced prostate protocols in magnetic resonance imaging]. / Klinischer Stellenwert kontrastmittelfreier Kurzprotokolle in der Magnetresonanztomographie.

BACKGROUND: According to the Prostate Imaging Reporting and Data System (PI-RADS) v2.1 multiparametric magnetic resonance imaging (mpMRI) with gadolinium-(Gd)-based contrast agents is the diagnostic standard of care in the detection of prostate cancer (PCa). Recent data suggest equivalent performance of biparametric MRI (bpMRI) and mpMRI in defined indications. OBJECTIVES: Evaluation of the current role of abbreviated or unenhanced protocols in MRI of the prostate in various clinical settings. MATERIALS AND METHODS: Evaluation of clinical trials, guidelines and expert opinions. RESULTS: The use of dynamic contrast-enhanced (DCE) MRI sequences is associated with contrast agent-associated risks and has significant impact on the imaging procedure and costs. Arguments for and against the use of contrast agent in prostate protocols as well as equivalence from bpMRI and mpMRI are discussed. CONCLUSIONS: Currently, bpMRI can only be performed if very good image quality is available and in the hands of a radiologist with extensive experience in reading prostate MRI. There is a need for prospective studies to qualify bpMRI as the diagnostic method for the primary diagnosis of PCa.

Usefulness of Biparametric Magnetic Resonance Imaging Combined With Prostate Specific Antigen Density in Pre-biopsy Detection of Clinically Insignificant Prostate Cancer.

BACKGROUND/AIM: The aim of this study was to identify simple and reliable factors to detect clinically insignificant prostate cancer (PC) for avoiding immediate prostate biopsies using biparametric magnetic resonance imaging (MRI), which consists of T2-weighted and diffusion-weighted imaging. PATIENTS AND METHODS: We retrospectively evaluated 427 men with suspected PC, who underwent biparametric MRI and standard 12-core transrectal prostate biopsy. MRI and prostate specific antigen density (PSAD) were analysed. To evaluate the combination of the two parameters, patients were divided into three groups (Group A: MRI negative and PSAD <0.23, Group B: MRI positive or PSAD ≥0.23, Group C: MRI positive and PSAD ≥0.23). A grade of ≥2 was defined as clinically significant PC. RESULTS: Clinically significant PC was detected in 46.5% of men with positive MRI findings, and 60.0% of men with PSAD ≥0.23. When combining MRI and PSAD, detection rates of clinically significant PC were 10.0%, 28.4% and 65.3% in group A, B and, C, respectively. CONCLUSION: Negative biparametric MRI findings with PSAD <0.23 might be a reliable evidence for avoiding immediate prostate biopsies.

Diagnostic Accuracy of Single-plane Biparametric and Multiparametric Magnetic Resonance Imaging in Prostate Cancer: A Randomized Noninferiority Trial in Biopsy-naïve Men.

BACKGROUND: Urological guidelines recommend multiparametric magnetic resonance imaging (mpMRI) in men with a suspicion of prostate cancer (PCa). The resulting increase in MRI demand might place health care systems under substantial stress. OBJECTIVE: To determine whether single-plane biparametric MRI (fast MRI) workup could represent an alternative to mpMRI in the detection of clinically significant (cs) PCa. DESIGN, SETTING, AND PARTICIPANTS: Between April 2018 and February 2020, 311 biopsy-naïve men aged ≤75 yr with PSA ≤15 ng/ml and negative digital rectal examination were randomly assigned to 1.5-T fast MRI (n = 213) or mpMRI (n = 98). INTERVENTION: All MRI examinations were classified according to Prostate Imaging-Reporting and Data System (PI-RADS) version 2. Men scored PI-RADS 1-2 underwent 12-core standard biopsy (SBx) and those with PI-RADS 4-5 on fast MRI or PI-RADS 3-5 on mpMRI underwent targeted biopsy in combination with SBx. Equivocal cases on fast MRI (PI-RADS 3) underwent mpMRI and then biopsy according to the findings. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The primary outcome was to compare the detection rate of csPCa in both study arms, setting a 10% difference for noninferiority. The secondary outcome was to assess the role of prostate-specific antigen density (PSAD) in ruling out men who could avoid biopsy among those with equivocal findings on fast MRI. RESULTS AND LIMITATIONS: The overall MRI detection rate for csPCa was 23.5% (50/213; 95% confidence interval [CI] 18.0-29.8%) with fast MRI and 32.7% (32/98; 95% CI 23.6-42.9%) with mpMRI (difference 9.2%; p = 0.09). The reproducibility of the study could have been affected by its single-center nature. CONCLUSIONS: Fast MRI followed by mpMRI in equivocal cases is not inferior to mpMRI in the detection of csPCa among biopsy-naïve men aged ≤75 yr with PSA ≤15 ng/ml and negative digital rectal examination. These findings could pave the way to broader use of MRI for PCa diagnosis. PATIENT SUMMARY: A faster MRI (magnetic resonance imaging) protocol with no contrast agent and fewer scan sequences for examination of the prostate is not inferior to the typical MRI approach in the detection of clinically significant prostate cancer. If our findings are confirmed in other studies, fast MRI could represent a time-saving and less invasive examination for men with suspicion of prostate cancer. This trial is registered at ClinicalTrials.gov as NCT03693703.

For men enrolled in active surveillance, pre-biopsy biparametric magnetic resonance imaging significantly reduces the risk of reclassification and disease progression after 1 year.

AIMS: To assess the level of disease progression at confirmatory staging biopsies after 1 year of active surveillance (AS) and compare the detection rate of significant prostate cancers (PCas) in patients who underwent pre-biopsy biparametric magnetic resonance imaging (bpMRI) before the first set of diagnostic transrectal ultrasonography-guided biopsies (TRUS-bx) with the detection rate in patients who did not undergo pre-biopsy bpMRI. MATERIALS AND METHODS: Comparison of two patient groups enrolled in AS. Patients in Group A (n = 127) underwent pre-biopsy bpMRI followed by TRUS-bx ± targeted biopsies. Patients in Group B (n = 127) were enrolled in AS based on biopsy results from TRUS-bx only. RESULTS: Overall, 6% of the patients in Group A and 20% of the patients in Group B had an upgrade in Gleason grade from insignificant to significant PCa at confirmatory staging biopsies (odds ratio [OR], 3.5; p = .002; 95% confidence interval [CI], 1.6-7.9). CONCLUSIONS: Patients who underwent pre-biopsy bpMRI before the first set of diagnostic biopsies had a reduced risk of reclassification and disease progression after 1 year of AS. Thus, pre-biopsy bpMRI improves the selection of men who should be enrolled in AS.

The Value of Multiparametric Magnetic Resonance Imaging Sequences to Assist in the Decision Making of Muscle-invasive Bladder Cancer.

Interim data from the PURE-01 study, using pembrolizumab before radical cystectomy in muscle-invasive bladder cancer (MIBC), suggested that multiparametric magnetic resonance imaging (mpMRI) was able to predict the pathologic response. Owing to the availability of novel effective therapies in MIBC, the possibility to assess tumor response easily has become exceedingly important. The primary objective of the present study was to evaluate the association between individual and combined MRI sequences, and the pathologic response in the final PURE-01 population. Images were internally evaluated and the diagnostic performance was analyzed for separate sequences, along with their combination. From February 2017 to December 2019, 143 patients were enrolled in PURE-01, and 123 with suitable paired imaging assessments before and after pembrolizumab tests (N = 246 mpMRI in total) were analyzed in relation to the pathologic response. The area under the curve (AUC) of the combination of all sequences to predict ypT0ypN0 response was 0.74. By excluding dynamic contrast enhancement (DCE) assessment, the AUC was 0.74. When looking at ypT1/a/is ypN0 response, the AUC was 0.87 in both cases. Without DCE, 95% of patients with no evidence of disease resulted in ypT1/a/is ypN0 and 65% ypT0ypN0 responders. In conclusion, the final results confirmed the reliability of mpMRI and suggested the opportunity to avoid intravenous gadolinium contrast to personalize bladder-sparing strategies in radiologically complete responders. PATIENT SUMMARY: We evaluated the reliability of multiparametric bladder magnetic resonance imaging to predict the pathologic response to pembrolizumab administered before radical cystectomy in muscle-invasive bladder cancer. We observed that this radiologic examination is promising in the attempt to identify opportunities to spare the bladder in selected, radiologically defined complete responders. We also observed that the use of intravenous gadolinium contrast can be avoided in future studies. ClinicalTrials.gov, number NCT02736266.

Additional Value of Dynamic Contrast-enhanced Sequences in Multiparametric Prostate Magnetic Resonance Imaging: Data from the PROMIS Study.

BACKGROUND: Multiparametric magnetic resonance imaging (MP-MRI) is established in the diagnosis of prostate cancer, but the need for enhanced sequences has recently been questioned. OBJECTIVE: To assess whether dynamic contrast-enhanced imaging (DCE) improves accuracy over T2 and diffusion sequences. DESIGN, SETTING, AND PARTICIPANTS: PROMIS was a multicentre, multireader trial, with, in this part, 497 biopsy-naïve men undergoing standardised 1.5T MP-MRI using T2, diffusion, and DCE, followed by a detailed transperineal prostate mapping (TPM) biopsy at 5 mm intervals. Likert scores of 1-5 for the presence of a significant tumour were assigned in strict sequence, for (1) T2 + diffusion and then (2) T2 + diffusion + dynamic contrast-enhanced images. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: For the primary analysis, the primary PROMIS outcome measure (Gleason score ≥4 + 3 or ≥6 mm maximum cancer length) on TPM was used, and an MRI score of ≥3 was considered positive. RESULTS AND LIMITATIONS: Sensitivity without and with DCE was 94% and 95%, specificity 37% and 38%, positive predictive value 51% and 51%, and negative predictive value 90% and 91%, respectively (p > 0.05 in each case). The number of patients avoiding biopsy (scoring 1-2) was similar (123/497 vs 121/497, p = 0.8). The number of equivocal scores (3/5) was slightly higher without DCE (32% vs 28% p = 0.031). The proportion of MRI equivocal (3/5) and positive (4-5) cases showing significant tumours were similar (23% and 71% vs 20% and 69%). No cases of dominant Gleason 4 or higher were missed with DCE, compared with a single case with T2 + diffusion-weighted imaging. No attempt was made to correlate lesion location on MRI and histology, which may be considered a limitation. Radiologists were aware of the patient's prostate-specific antigen. CONCLUSIONS: Contrast adds little when MP-MRI is used to exclude significant prostate cancer. PATIENT SUMMARY: An intravenous injection of contrast may not be necessary when magnetic resonance imaging is used as a test to rule out significant tumours in the prostate.

Round table: arguments in supporting abbreviated or biparametric MRI of the prostate protocol.

Prostate Imaging Reporting and Data System (PI-RADS) version 2.1 update, in the attempt to improve clinical guidelines for multiparametric magnetic resonance imaging (mpMRI) of the prostate, has clear limitations. The role of dynamic contrast-enhanced sequences is not defined, precise guidance on the clinical management (biopsy or clinical surveillance) for score 3 lesions [equivocal for clinical significant prostate cancer (sPCa)] is not offered and criteria for lesions interpretation remain difficult and subjective. We report criteria and arguments in supporting the use of abbreviated or biparametric prostate MRI protocol in clinical practice for detection and management of PCa.

High Diagnostic Performance of Short Magnetic Resonance Imaging Protocols for Prostate Cancer Detection in Biopsy-naïve Men: The Next Step in Magnetic Resonance Imaging Accessibility.

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.

Using biparametric MRI radiomics signature to differentiate between benign and malignant prostate lesions.

PURPOSE: To investigate the efficiency of radiomics signature in discriminating between benign and malignant prostate lesions with similar biparametric magnetic resonance imaging (bp-MRI) findings. EXPERIMENTAL DESIGN: Our study consisted of 331 patients underwent bp-MRI before pathological examination from January 2013 to November 2016. Radiomics features were extracted from peripheral zone (PZ), transition zone (TZ), and lesion areas segmented on images obtained by T2-weighted imaging (T2WI), diffusion-weighted imaging (DWI), and its derivative apparent-diffusion coefficient (ADC) imaging. The individual prediction model, built using the clinical data and biparametric MRI features (Bp signature), was prepared using data of 232 patients and validated using data of 99 patients. The predictive performance was calculated and demonstrated using receiver operating characteristic (ROC) curves, calibration curves, and decision curves. RESULTS: The Bp signature, based on the six selected radiomics features of bp-MRI, showed better discrimination in the validation cohort (area under the curve [AUC], 0.92) than on each subcategory images (AUC, 0.81 on T2WI; AUC, 0.77 on DWI; AUC, 0.89 on ADC). The differential diagnostic efficiency was poorer with the clinical model (AUC, 0.73), built using the selected independent clinical risk factors with statistical significance (P < 0.05), than with the Bp signature. Discrimination efficiency improved when including the Bp signature and clinical factors [i.e., the individual prediction model (AUC, 0.93)]. CONCLUSION: The Bp signature, based on bp-MRI, performed better than each single imaging modality. The individual prediction model including the radiomics signatures and clinical factors showed better preoperative diagnostic performance, which could contribute to clinical individualized treatment.

Prostate cancer detection with biparametric magnetic resonance imaging (bpMRI) by readers with different experience: performance and comparison with multiparametric (mpMRI).

PURPOSE: To study the detection of clinically significant prostate cancer (PCa) by readers with different experience, comparing performance with biparametric magnetic resonance imaging (bmMRI) and with the reference multiparametric (mpMRI). METHODS: Retrospective analysis of 68 patients with mpMRI of the prostate at 1.5 Tesla using a 32 phased-array coil. Forty-five patients (cases) underwent radical prostatectomy, whereas 23 (controls) had a negative prostate biopsy and ≥ 2.5 years of negative follow-up. Six observers (two with 1000 cases interpreted, two with 300, two with 100) performed the analysis first with bpMRI including diffusion-weighted imaging (DWI), apparent diffusion coefficient (ADC) maps and T2-weighted (T2W) imaging in three planes and, after 1 month, with mpMRI, adding dynamic contrast enhancement (DCE). The performance was quantified by sensitivity (SNS), specificity (SPC) and area under the curve (AUC) of the ROC (Receiver Operating Characteristics) procedure. RESULTS: Concordance within observers of equivalent experience was good (weighted Cohen's k ≈ 0.7). The two expert readers performed as well in bpMRI as in mpMRI (SNS = 0.91-0.96, AUC = 0.86-0.93; p ≥ 0.10); readers with 300 cases performed well in mpMRI, but significantly worse in bpMR: SNS = 0.58 versus 0.91 (p < 0.0001) and AUC = 0.73 versus 0.86 (p = 0.01); the limited experience of readers with 100 cases showed in mpMRI (SNS = 0.71; AUC = 0.77) and even more in bpMRI (SNS = 0.50; AUC = 0.68). CONCLUSION: The study revealed the impact of the readers' experience when using bpMRI. The bpMRI without contrast media was a valid alternative for expert readers, whereas less experienced ones needed DCE to significantly boost SNS and AUC. Results indicate 700-800 cases as threshold for reliable interpretation with bpMRI.