Integration of prostate biopsy results with pre-biopsy multiparametric MRI findings improves local staging of prostate cancer

Abstract

Purpose: To assess the added value of histological information for local staging of prostate cancer (PCa) by comparing the accuracy of multiparametric MRI alone (mpMRI) and mpMRI with biopsy Gleason grade (mpMRI+Bx). Methods: 133 consecutive patients who underwent preoperative 3T MRI and subsequent radical prostatectomy for PCa were included in this single centre retrospective study. mpMRI imaging was reviewed independently by two uroradiologists for the presence of extracapsular extension (ECE) and seminal vesicle invasion (SVI) on a 5-point Likert scale. For second reads, the radiologists received results of targeted fused MR/US biopsy (mpMRI+Bx) prior to re-staging. Results: The median patient age was 63 years (IQR 58-67 years) and median PSA was 6.5 ng/mL (IQR 5.0-10.0 ng/mL). ECE was present in 85/133 (63.9%) patients and SVI was present in 22/133 (16.5%) patients. For ECE prediction, mpMRI showed sensitivity and specificity of 63.5% and 81.3%, respectively, compared to 77.7% and 81.3% achieved by mpMRI+Bx. At an optimal cut-off value of Likert score  3, AUCs was 0.85 for mpMRI+Bx and 0.78 for mpMRI, p < 0.01. For SVI prediction, AUC was 0.95 for mpMRI+Bx compared to 0.92 for mpMRI; p = 0.20. Inter-reader agreement for ECE and SVI prediction was substantial for mpMRI (k range, 0,78 - 0.79) and mpMRI+Bx (k range, 0.74 - 0.79). Conclusions: MpMRI+Bx showed superior diagnostic performance with an increased sensitivity for ECE prediction but no significant difference for SVI prediction. Inter-reader agreement was substantial for both protocols. Integration of biopsy information adds value when staging prostate mpMRI.