Comparison of bi- and multiparametric magnetic resonance imaging to select men for active surveillance.

BACKGROUND: Active surveillance of men with prostate cancer relies on accurate risk assessments because it aims to avoid or delay invasive therapies and reduce overtreatment. PURPOSE: To compare the diagnostic performance of pre-biopsy biparametric magnetic resonance imaging (MRI) with confirmatory multiparametric MRI in selecting men for active surveillance. MATERIAL AND METHODS: The study population included biopsy-naïve men with clinical suspicion of prostate cancer undergoing biparametric MRI followed by combined (standard plus MRI targeted) biopsies. Men diagnosed with prostate cancer who were subsequently enrolled in active surveillance and underwent a confirmatory multiparametric MRI within three months of diagnosis were included in the study. Discrepancies between the pre-biopsy biparametric MRI and the confirmatory multiparametric MRI were assessed. RESULTS: Overall, 101 men (median age = 64 years; median prostate-specific-antigen level = 6.3 ng/mL) were included. Nine patients were re-biopsied after multiparametric MRI for the following reasons: suspicion of targeting error (three patients); a new suspicious lesion detected by multiparametric MRI (five patients); and an increase in tumor volume (one patient) compared with biparametric MRI. Confirmatory biopsies showed a Gleason grade group (GG) upgrade of ≥2 in 4/6 patients with suspicion of more advanced disease (missed suspicious lesion, increase in tumor volume) on multiparametric MRI. However, although multiparametric MRI subsequently detected a GG ≥ 2 prostate cancer lesion missed by biparametric MRI in 4% (4/101) of included men, the difference did not reach statistical significance (McNemar, P = 0.133). CONCLUSION: Biparametric MRI could be used to select men eligible for active surveillance and a confirmatory multiparametric MRI performed shortly after inclusion seems unnecessary.

Prebiopsy Biparametric Magnetic Resonance Imaging Combined with Prostate-specific Antigen Density in Detecting and Ruling out Gleason 7-10 Prostate Cancer in Biopsy-naïve Men.

BACKGROUND: Multiparametric magnetic resonance imaging (MRI) combined with prostate-specific-antigen density (PSAd) enhances the detection of significant prostate cancer (sPCa). However, it is unclear whether simple biparametric (bp) MRI, which reduces scan sequences, time, and cost, may be an equally effective noninvasive tool for detecting and ruling out sPCa and avoiding biopsies in biopsy-naïve men. OBJECTIVE: To assess the diagnostic accuracy, predictive values, and best biopsy strategy combining bpMRI and PSAd in detecting and ruling out sPCa (Gleason score ≥7). DESIGN, SETTING, AND PARTICIPANTS: Assessment of 808 biopsy-naïve men with clinical suspicion of localised PCa (prostate-specific antigen <20ng/ml, rectal examination

Assessment of the Diagnostic Accuracy of Biparametric Magnetic Resonance Imaging for Prostate Cancer in Biopsy-Naive Men: The Biparametric MRI for Detection of Prostate Cancer (BIDOC) Study.

Importance: Multiparametric magnetic resonance imaging (MRI) enhances detection and risk stratification for significant prostate cancer but is time-consuming (approximately 40 minutes) and expensive. Rapid and simpler (approximately 15-minute) biparametric MRI (bpMRI) using fewer scan sequences could be implemented as a prostate MRI triage test on a larger scale before performing biopsies. Objectives: To assess the diagnostic accuracy and negative predictive value (NPV) of a novel bpMRI method in biopsy-naive men in detecting and ruling out significant prostate cancer in confirmatory biopsies. Design, Setting, and Participants: A single-institutional, paired, prospective cohort study of biopsy-naive men with clinical suspicion of prostate cancer from November 1, 2015, to June 15, 2017. Interventions: All patients underwent bpMRI (T2-weighted and diffusion-weighted imaging) followed by standard transrectal ultrasound-guided biopsies (all men) and targeted biopsies of men with suspicious bpMRI findings. Main Outcomes and Measures: Suspicion grades of bpMRI, biopsy results, and NPV of bpMRI were evaluated for detection of or ruling out significant prostate cancer (Gleason score ≥4 + 3 or maximum cancerous core length >50% for Gleason score 3 + 4). We compared the diagnostic performance of standard biopsies in all men vs standard plus targeted (combined) biopsies restricted to men with suspicious bpMRI findings. The reference standard was combined biopsy results from all men. Results: A total of 1020 men were enrolled, with a median age of 67 years (interquartile range, 61-71 years) and a median prostate-specific antigen level of 8.0 ng/mL (interquartile range, 5.7-13.0 ng/mL). Combined biopsies detected any and significant prostate cancer in 655 of 1020 men (64%) and 404 of 1020 men (40%), respectively. Restricting combined biopsies to men with suspicious bpMRI findings meant 305 of 1020 men (30%) with low-suspicious bpMRIs could avoid prostate biopsies (biopsy in 715 men with suspicious bpMRIs vs all 1020 men who required standard biopsies [70%]; P < .001). Significant prostate cancer diagnoses were improved by 11% (396 vs 351 men; P < .001), and insignificant prostate cancer diagnoses were reduced by 40% (173 vs 288 men; P < .001) compared with our current diagnostic standard, standard biopsies alone in all men. The NPV of bpMRI findings in ruling out significant prostate cancer was 97% (95% CI, 95%-99%). Conclusions and Relevance: Low-suspicion bpMRI has a high NPV in ruling out significant prostate cancer in biopsy-naive men. Using a simple and rapid bpMRI method as a triage test seems to improve risk stratification and may be used to exclude aggressive disease and avoid unnecessary biopsies with its inherent risks. Future studies are needed to fully explore its role in clinical prostate cancer management.

Magnetic resonance imaging-guided biopsies may improve diagnosis in biopsy-naive men with suspicion of prostate cancer.

INTRODUCTION: The purpose of this pilot study was to investigate whether a short prostate biparametric magnetic resonance imaging (bp-MRI) protocol provides a valuable diagnostic addition for biopsy guidance in biopsy-naive men with a suspicion of prostate cancer (PCa). METHODS: A total of 62 biopsy-naive patients referred to a systematic transrectal ultrasound biopsy (TRUS-bx) due to suspicion of PCa were prospectively enrolled. Bp-MRI was performed before biopsy. All lesions were scored according to the modified Prostate Imaging Reporting and Data System (PI-RADS) version 2. All patients underwent TRUS-bx followed by bp-MRI-guided biopsies (bp-MRI-bx) under MRI/TRUS image fusion from any bp-MRI suspicious lesions not obviously targeted by TRUS-bx. RESULTS: PCa was found in 42 (68%) and 32 (52%) patients by TRUS-bx and bp-MRI-bx, respectively. Bp-MRI-bx de-tected PCa in one patient who had been missed by TRUS-bx, and found the highest Gleason score (GS) in 13 (30%) patients leading to an overall GS upgrade in six (14%) patients. Bp-MRI missed nine patients with GS = 6 and two with a GS = 7 (3 + 4), all of whom were diagnosed by TRUS-bx. CONCLUSIONS: Addition of bp-MRI-bx to routine TRUS-bx seems feasible in biopsy-naive patients and may improve the detection of aggressive PCa in first-round biopsies. This pilot study thus provides an incentive for a larger investigation. FUNDING: Costs were covered by the Department of Radiology, Herlev Hospital, Denmark. TRIAL REGISTRATION: This study was registered with the Danish Data Protection Agency (HEH-2015-054, I-Suite no: 03775) and with the Committee for Health Research Ethics (no. H-15009341).

Biparametric versus multiparametric MRI in the diagnosis of prostate cancer.

BACKGROUND: Since multiparametric magnetic resonance imaging (mp-MRI) of the prostate exceeds 30 min, minimizing the evaluation time of significant (Gleason scores > 6) prostate cancer (PCa) would be beneficial. A reduced protocol might be sufficient for the diagnosis. PURPOSE: To study whether a short unenhanced biparametric MRI (bp-MRI) matches mp-MRI in detecting significant PCa. MATERIAL AND METHODS: A total of 204 men (median age, 65 years; mean ± SD, 64.1; range 45-75 years; median serum PSA level, 14 ng/mL; range, 2.2-120 ng/mL; median prostate volume, 60 mL; range, 23-263 mL) fulfilled the criteria for being enrolled. They underwent mp-MRI and prostate biopsy from January through June 2014. Of the included patients, 9.3% underwent prostatectomy, 90.7% had TRUS-bx, and 10.8 had MRI-targeted TRUS-bx. Two radiologists separately assessed the mp-MRI examination (T2-weighted [T2W] imaging, diffusion-weighted imaging [DWI], apparent diffusion coefficient map [ADC-map] and dynamic contrast-enhanced imaging [DCE]). Two months later, the bp-MRI version (T2W imaging, DWI, and ADC-map) was evaluated. RESULTS: Reader 1: Assessing mp-MRI: 0 false negatives, sensitivity of 1, and specificity 0.04. Assessing bp-MRI: four false negatives, sensitivity of 0.94, and specificity 0.15. Reader 2: Assessing mp-MRI: five false negatives, sensitivity of 0.93, and specificity 0.16. Assessing bp-MRI: three false negatives, sensitivity of 0.96, and specificity 0.15. Intra-reader agreement Cohen's Kappa (κ) was 0.87 for reader 1 (95% confidence interval [CI], 0.83-0.92) and 0.84 for reader 2 (95% CI 0.78-0.89). CONCLUSION: Bp-MRI is as good as mp-MRI at detecting PCa. A large prospective study seems to be strongly warranted.