Detection and Localization of Prostate Cancer at 3-T Multiparametric MRI Using PI-RADS Segmentation

Pornphan Wibulpolprasert; Steven S Raman; William Hsu; Daniel J A Margolis; Nazanin H Asvadi; Pooria Khoshnoodi; Amin Moshksar; Nelly Tan; Preeti Ahuja; Cleo K Maehara; Jiaoti Huang; James Sayre; David S K Lu; Robert E Reiter

doi:10.2214/AJR.18.20113

Detection and Localization of Prostate Cancer at 3-T Multiparametric MRI Using PI-RADS Segmentation

AJR Am J Roentgenol. 2019 Jun;212(6):W122-W131. doi: 10.2214/AJR.18.20113. Epub 2019 Apr 17.

Authors

Affiliations

¹ Department of Diagnostic and Therapeutic Radiology, Faculty of Medicine, Ramathibodi Hospital, 270 Rama VI Rd, Bangkok, Thailand 10400.
² Department of Radiology, David Geffen School of Medicine at UCLA, Los Angeles, CA.
³ Department of Urology, David Geffen School of Medicine at UCLA, Los Angeles, CA.
⁴ Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA.

PMID: 30995090
DOI: 10.2214/AJR.18.20113

Abstract

OBJECTIVE. The purpose of this study is to determine the overall and sector-based performance of 3-T multiparametric MRI for prostate cancer (PCa) detection and localization by using Prostate Imaging-Reporting and Data System version 2 (PI-RADSv2) scoring and segmentation compared with whole-mount histopathologic analysis. MATERIALS AND METHODS. Multiparametric 3-T MRI examinations of 415 consecutive men were compared with thin-section whole-mount histopathologic analysis. A genitourinary radiologist and pathologist collectively determined concordance. Two radiologists assigned PI-RADSv2 categories and sectoral location to all detected foci by consensus. Tumor detection rates were calculated for clinical and pathologic (Gleason score) variables. Both rigid and adjusted sector-matching models were used to account for fixation-related issues. RESULTS. The 415 patients had 863 PCa foci (52.7% had a Gleason score ≥ 7, 61.9% were ≥ 1 cm, and 90.4% (375/415) of index lesions were ≥ 1 cm) and 16,185 prostate sectors. Multiparametric MRI enabled greater detection of PCa lesions 1 cm or larger (all lesions vs index lesions, 61.6% vs 81.6%), lesions with Gleason score greater than or equal to 7 (all lesions vs index lesions, 71.4% vs 80.9%), and index lesions with both Gleason score greater than or equal to 7 and size 1 cm or larger (83.3%). Higher sensitivity was obtained for adjusted versus rigid tumor localization for all lesions (56.0% vs 28.5%), index lesions (55.4% vs 34.3%), lesions with Gleason score greater than or equal to 7 (55.7% vs 36.0%), and index lesions 1 cm or larger (56.1% vs 35.0%). Multiparametric 3-T MRI had similarly high specificity (96.0-97.9%) for overall and index tumor localization with adjusted and rigid sector-matching approaches. CONCLUSION. Using 3-T multiparametric MRI and PI-RADSv2, we achieved the highest sensitivity (83.3%) for the detection of lesions 1 cm or larger with Gleason score greater than or equal to 7. Sectoral localization of PCa within the prostate was moderate and was better with an adjusted model than with a rigid model.

Keywords: localization; multiparametric MRI; prostate cancer detection; prostatectomy.