Evaluation of the accuracy of multiparametric MRI for predicting prostate cancer pathology and tumour staging in the real world: an multicentre study

Abstract

Objectives To assess the accuracy of multiparametric magnetic resonance imaging (mpMRI) for the detection of significant prostate cancer in men undergoing radical prostatectomy (RP) in an Australian multicentre setting, and to assess concordance between mpMRI and RP for local tumour staging and index lesion locations. Patients and Methods Men who underwent mpMRI within 12 months of RP between January 2013 and August 2016 at three Australian sites were included (Central Coast, NSW, St Vincents Hospital, Melbourne, Vic., and Bendigo Hospital, Vic.). The results of mpMRI were compared with the final RP specimen to analyse the performance of mpMRI for significant prostate cancer detection, index lesion localization, prediction of T3 disease and lymph node metastasis. A comparison between mpMRI cases performed using the technical and reporting specifications of Prostate Imaging Reporting and Data System (PI‐RADS) version 1 and version 2 was also performed. Data analysis was performed using spss 24.0. Results A total of 235 cases were included for analysis. mpMRI PI‐RADS score ≥3 had a 91% sensitivity and 95% positive predictive value (PPV) for significant prostate cancer at RP. The overall concordance between index lesion location on mpMRI and RP specimen was 75%. The sensitivity for predication of significant prostate cancer was higher in the PI‐RADS version 2 cases compared with PI‐RADS version 1 (87–99%; P = 0.005). Index lesion concordance was higher in the PI‐RADS version 2 group (68% vs 91%; P = 0.002). mpMRI had a 38% sensitivity, 95% specificity, 90% PPV and 57% negative predictive value for extraprostatic disease. Sensitivity for prediction of T3 disease improved from 30% to 62% (P = 0.008) with PI‐RADS version 2. Conclusions In patients undergoing RP, an abnormal mpMRI is highly predictive (95% PPV) of significant prostate cancer, with an index lesion concordance of 75%. There has been a significant improvement in accuracy after the adoption of PI‐RADS version 2 technical specifications and reporting criteria; however; further study is required to determine if this is attributable to improved experience with mpMRI or changes in the PI‐RADS system.

The role of multiparametric resonance and biopsy in prostate cancer detection: comparison with definitive histological report after laparoscopic/robotic radical prostatectomy

“…Due to these findings, we utilized in our study a biopsy protocol that comprehended a combined approach of systematic and fusion targeted biopsy, in order to obtain the highest possible accuracy. Kam et al [31], evaluating the accuracy of mpMRI in detecting PCa and tumor staging, reported, on 235 patients, an overall index lesion location concordance between mpMRI and RP histologic report of 75% with a sensitivity that reached 91% in the detection of clinically significant PCa (GS ≥ 7). In a previous study [32], the same authors reported, on 121 patients, a concordance rate for GS between combined biopsy (fusion plus standard) and final histologic report of 58%.…”

The Role of Magnetic Resonance Imaging and Positron Emission Tomography/Computed Tomography in the Primary Staging of Newly Diagnosed Prostate Cancer: A Systematic Review of the Literature

“…However, the sample size was relatively small. Kam et al [41] observed significant improvement in sensitivity for the prediction of EPE (from 30% to 60%) when applying PIRADS v2 compared with v1 in 235 patients. However, this study lacked information on patient characteristics, MRI findings, event rate, confidence intervals, or further outcomes for the different groups.…”

Funding of prostate magnetic resonance imaging leads to fewer biopsies and potential savings to health systems in the management of prostate cancer

“…Our present analysis suggested a reduction of 414 biopsies/month (95% CI 120, 708; P =0.007), (or 4968 ± 3528 biopsies annually) correlating to the availability of mpMRIp. The study period encompassed PI‐RADS v1 and v2, although both have been validated to have a high negative predictive value (82% for prostate cancer, and 88% for clinically significant prostate cancer, International Society of Urological Pathology [ISUP] ≥2), with PI‐RADS v2 having equivalent specificity but improved sensitivity, enabling clinicians to use a ‘rule out’ strategy for avoiding invasive prostate biopsies, which may explain this result [8,10,23,24].…”

“…trial [PRECISION]) [7]. A standardised reporting tool for mpMRIp, the Prostate Imaging -Reporting and Data System (PI-RADS) version 1 (v1) and the current version 2 (v2) have been validated to increase the positive and negative predictive values of performing a biopsy [6][7][8][9][10]. Multiple studies show good correlation of mpMRIp grading to final histopathology confirmed with radical prostatectomy specimens [10][11][12].…”

“…A standardised reporting tool for mpMRIp, the Prostate Imaging -Reporting and Data System (PI-RADS) version 1 (v1) and the current version 2 (v2) have been validated to increase the positive and negative predictive values of performing a biopsy [6][7][8][9][10]. Multiple studies show good correlation of mpMRIp grading to final histopathology confirmed with radical prostatectomy specimens [10][11][12]. Long-term follow-up of patients with low-risk prostate cancer indicates men on active surveillance (AS) can avoid protocol biopsies in favour of mpMRI and PSA surveillance with targeted biopsies when indicated [13].…”