Impact of the PI-QUAL MRI quality score on histopathological up-staging from MRI fusion biopsy to final prostatectomy specimen

Abstract

Purpose The qualitative heterogeneity of multiparametric MRI (mpMRI) poses significant challenges for the diagnostic pathway of prostate cancer (PCa). The Prostate Imaging Quality Score (PI-QUAL) is a novel tool for the qualitative assessment of mpMRI. Aim of this study was to evaluate the impact of PI-QUAL on consistency of radiological to pathological T-stage. Methods Patients undergoing MRI-TRUS fusion biopsy and radical prostatectomy (RP) from 01/2016 to 03/2024 were retrospectively included. PI-QUAL was determined by two expert radiologists and categorised: inadequate (1–2), sufficient (3) and optimal (4–5). Primary endpoint was upstaging from locally confined disease in mpMRI (mrT ≤ 2) to advanced in RP-specimen (pT ≥ 3a). Variables were compared using analysis of variance and χ2 or Fisher’s exact test. Uni- and multivariate binary regression identified independent predictors. Results Of 349 patients included, 18 had PI-QUAL 1–2, 44 PI-QUAL 3 and 287 PI-QUAL 4–5. Patient characteristics, PI-RADS scores and biopsy counts were balanced between these groups. Upstaging from mrT ≤ 2 to pT ≥ 3a was significantly more frequent in PI-QUAL 1–2 (22.4%) and PI-QUAL 3 (22.7%) compared to PI-QUAL 4–5 (10.8%) (p = 0.031). Suboptimal mpMRI harbours an increased risk of upstaging (HR 2.22; 95% CI 1.05–4.71; p = 0.037). Optimal mpMRI quality independently predicts higher PI-RADS grading (PI-RADS ≥ 4) (HR 2.27; 95% CI 1.02-5.00; p = 0.043). Conclusion PI-QUAL (≤ 3) significantly influences PI-RADS grading and predicts for upstaging from radiological to pathological staging. In case of suboptimal image quality, repetition of mpMRI should be considered.