Dataset Information

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.

ABSTRACT:

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.

SUBMITTER: Boesen L

PROVIDER: S-EPMC6324414 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:Take Home Message In biopsy-naïve patients suspected for prostate cancer, we propose that in case of nonsuspicious multiparametric magnetic resonance imaging (mpMRI), one could abstain from systematic biopsies after careful shared decision-making. Systematic biopsies add a substantial number of clinically significant prostate cancer cases and should not be omitted in case of suspicious mpMRI. Background It remains uncertain whether transrectal ultrasound (TRUS)-guided systematic biopsies can be omitted and rely solely on multiparametric magnetic resonance imaging–targeted biopsies (MRI-TBx) in biopsy-naïve men suspected of prostate cancer (PCa). Objective To compare PCa detection in biopsy-naïve men between systematic biopsy and MRI-TBx. Design, setting, and participants A prospective cohort study was conducted in a Dutch teaching hospital. Consecutive patients with suspected PCa, no history of biopsy, and no clinical suspicion of metastasis underwent both TRUS-guided systematic biopsies and MRI-TBx by multiparametric magnetic resonance imaging (mpMRI)-ultrasound fusion, including sham biopsies in case of negative mpMRI. Outcome measurements and statistical analysis Clinically significant PCa (csPCa), defined as group ≥2 on the International Society of Urological Pathology grading, was detected. Results and limitations The overall prevalence of csPCa, irrespective of biopsy technique, was 37.4% (132/353) in our population. MRI-TBx were performed in 263/353 (74.5%) patients with suspicious mpMRI (Prostate Imaging Reporting and Data System [PI-RADS] ≥3). The detection rates for csPCa were 39.5% for MRI-TBx and 42.9% for systematic biopsies. The added values, defined as the additional percentages of patients with csPCa detected by adding one biopsy technique, were 8.7% for the systematic biopsies and 5.3% for MRI-TBx. In patients with nonsuspicious mpMRI, five cases (6%) of csPCa were found by systematic biopsies. Conclusions This study in biopsy-naïve patients suspected for PCa showed that systematic biopsies have added value to MRI-TBx alone in patients with mpMRI PI-RADS >2. Patient summary We studied magnetic resonance imaging (MRI)-guided prostate biopsy for diagnosing prostate cancer and compared it with the standard method of prostate biopsy. Standard systematic biopsies cannot be omitted in patients with suspicious MRI, as they add to the detection of significant prostate cancer.

Project description:BACKGROUND:Magnetic resonance imaging (MRI) combined with targeted biopsy (TB) is increasingly used in men with clinically suspected prostate cancer (PCa), but the long acquisition times, high costs, and inter-center/reader variability of routine multiparametric prostate MRI limit its wider adoption. METHODS AND FINDINGS:The aim was to validate a previously developed unique MRI acquisition and reporting protocol, IMPROD biparametric MRI (bpMRI) (NCT01864135), in men with a clinical suspicion of PCa in a multi-institutional trial (NCT02241122). IMPROD bpMRI has average acquisition time of 15 minutes (no endorectal coil, no intravenous contrast use) and consists of T2-weighted imaging and 3 separate diffusion-weighed imaging acquisitions. Between February 1, 2015, and March 31, 2017, 364 men with a clinical suspicion of PCa were enrolled at 4 institutions in Finland. Men with an equivocal to high suspicion (IMPROD bpMRI Likert score 3-5) of PCa had 2 TBs of up to 2 lesions followed by a systematic biopsy (SB). Men with a low to very low suspicion (IMPROD bpMRI Likert score 1-2) had only SB. All data and protocols are freely available. The primary outcome of the trial was diagnostic accuracy-including overall accuracy, sensitivity, specificity, negative predictive value (NPV), and positive predictive value-of IMPROD bpMRI for clinically significant PCa (SPCa), which was defined as a Gleason score ? 3 + 4 (Gleason grade group 2 or higher). In total, 338 (338/364, 93%) prospectively enrolled men completed the trial. The accuracy and NPV of IMPROD bpMRI for SPCa were 70% (113/161) and 95% (71/75) (95% CI 87%-98%), respectively. Restricting the biopsy to men with equivocal to highly suspicious IMPROD bpMRI findings would have resulted in a 22% (75/338) reduction in the number of men undergoing biopsy while missing 4 (3%, 4/146) men with SPCa. The main limitation is uncertainty about the true PCa prevalence in the study cohort, since some of the men may have PCa despite having negative biopsy findings. CONCLUSIONS:IMPROD bpMRI demonstrated a high NPV for SPCa in men with a clinical suspicion of PCa in this prospective multi-institutional clinical trial. TRIAL REGISTRATION:ClinicalTrials.gov NCT02241122.