Role of the Prostate Imaging Quality PI-QUAL Score for Prostate Magnetic Resonance Image Quality in Pathological Upstaging After Radical Prostatectomy: A Multicentre European Study

Background: Increasing use of multiparametric magnetic resonance imaging (mpMRI) has come with heterogeneity in image quality. The Prostate Imaging Quality (PI-QUAL) score is under scrutiny to assess its usefulness in predicting clinical outcomes.Objective: To compare upstaging of localized disease on mpMRI (mrT2) to locally invasive disease in radical prostatectomy (RP) specimens (>= pT3a) in relation to PI-QUAL.Design, setting, and participants: Patients treated with RP between 2015 and 2020 who underwent 1.5-3-T mpMRI within 6 mo before surgery and had systematic and mpMRI-US targeted biopsies were included. mpMRI scans were retrospectively assigned a PI-QUAL score, and prospectively acquired Prostate Imaging-Recording and Data System (PI-RADS) scores (version 2.0 or 2.1) were used. PI-QUAL scores were categorized as nondiagnostic (PI-QUAL <3), sufficient (PI-QUAL 3), or optimal (PI-QUAL >3). Outcome measurements and statistical analysis: We assessed the relationship between the PI-QUAL score and upstaging using multivariate logistic regression. mpMRI, clin-ical, and pathological findings were compared using v2 tests and analysis of variance.Results and limitations: We identified 351 patients, of whom 40 (11.4%) had PI-QUAL <3, 57 (16.3%) had PI-QUAL 3, and 254 (72.3%) had PI-QUAL >3 scores. The distribu-tion of PI-QUAL <3 (0-33.6%; p < 0.001) and PI-QUAL >3 (37.3-100%; p < 0.001) scores varied widely among centers. PI-QUAL >3 in comparison to PI-QUAL <3 was associated with a lower rate of upstaging (19% vs 35%; p = 0.02), greater detec-tion of mrT3a and mrT3b prostate cancer (17.0% vs 2.5%; p = 0.016), a higher rate of PI-RADS 5 lesions (47% vs 27.5%; p = 0.002), a higher number of suspicious lesion (PI-RADS >= 3: 34.7% vs 15%; p = 0.012), and higher detection rates for aggregated (50.7% vs 22.5%; p = 0.001) and late (21.2% vs 0%; p < 0.001) extraprostatic exten-sion. On multivariate analysis, PI-QUAL<3 was associated with more frequent upstaging in the RP specimen (odds ratio 3.4; p = 0.01).Conclusions: In comparison to PI-QUAL >= 3, PI-QUAL <3 was significantly associated with a higher rate of upstaging from organ-confined disease on mpMRI to locally advanced disease on pathology, lower detection rates for PI-RADS 5 lesions and extraprostatic extension, and a lower number of suspicious lesions. Patient summary: Poor image quality for magnetic resonance imaging (MRI) scans of the prostate is associated with underestimation of the stage of prostate cancer.(c) 2022 The Authors. Published by Elsevier B.V. on behalf of European Association of Urology. This is an open access article under the CC BY license (http://creativecommons. org/licenses/by/4.0/).

Automated summary

PI-QUAL <3 is associated with higher rate of disease upstaging, lower detection rates of PI-RADS 5 lesions and suspicious lesions, and lower detection rates of extraprostatic extension.