[Implications of PI RADS Version 1 and Updated Version 2 on the Scoring of Prostatic Lesions in Multiparametric MRI]
BACKGROUND A revised version of the PI RADS scoring system has been introduced and score related variability between version 1 and 2 may be suspected. This study aimed to assess the PI RADS scores derived from version 1 (v1) and the updated version 2 (v2) MATERIAL AND METHODS 61 patients with biopsy proven prostate cancer (PCa) and 90 lesions detected on pre biopsy 3 Tesla multiparametric MRI were included in this retrospective analysis. 2 experienced radiologists scored all lesions in consensus. Lesion scores differing between PI RADS v1 and v2 were further analyzed. Histology data from radical prostatectomy (RP) were included when available. RESULTS The PI RADS v1 and v2 score differed in 52% of patients (32/61) and in 39% of lesions (35/90) On a lesion basis, the reason for the differences were related to sum score in v1 vs. categorical system in v2 in 51% (18/35) of lesions, cutoff between PI RADS 4 and 5 based on lesion size in v2 as opposed to the sum score in v1 in 31% (11/35) and were inconclusive in 17% (6/35) The RP subgroup indicates enhanced detection of PCas with GS 3+3 and GS 3+4 in v2. CONCLUSION PI RADS scores of prostatic lesions frequently differed between v1 and v2, the major reasons for these differences being score related. In men undergoing RP, PI RADS v2 improved detection of low risk PCa, but did not increase accuracy for discrimination of GS 3+4 vs. GS>=4+3 compared to v1. Urologists should be aware of the system related differences when interpreting PI RADS scores.
Aktuelle Urologie