Comparison of the PI-RADS 2.1 scoring system to PI-RADS 2.0: Impact on diagnostic accuracy and inter-reader agreement

Abstract

To assess the value of the PI-RADS 2.1 scoring system in the detection of prostate cancer on multiparametric MRI in comparison to the standard PI-RADS 2.0 system and to assess its inter-reader variability. Materials and methods This IRB-approved study included 229 patients undergoing multiparametric prostate MRI prior to MRI-guided TRUS-based biopsy, which were retrospectively recruited from our prospectively maintained institutional database. Two readers with high (reader 1, 6 years) and low (reader 2, 2 years) level of expertise identified the lesion with the highest PI-RADS score for both version 2.0 and 2.1 for each patient. Inter-reader agreement was estimated, and diagnostic accuracy analysis was performed. Results Inter-reader agreement on PI-RADS scores was fair for both version 2.0 (kappa: 0.57) and 2.1 (kappa: 0.51). Detection rates for prostate cancer (PCa) and clinically significant prostate cancer (csPCa) were almost identical for both PI-RADS versions and higher for the more experienced reader (AUC, Reader 1: PCa, 0.881-0.887, csPCa, 0.874-0.879; Reader 2: PCa, 0.765, csPCa, 0.746-0.747; both p > 0.05), both when using a PI-RADS score of � 4 and �3 as indicators for positivity for cancer. Conclusions The new PI-RADS 2.1 scoring system showed comparable diagnostic performance and inter-reader variability compared to version 2.0. The introduced changes in the version 2.1 seem only to take effect in a very small number of patients.

Inter-reader agreement of the prostate imaging reporting and data system version v2.1 for detection of prostate cancer: A systematic review and meta-analysis

“…The mean patient age was 63.1-73 years and with a PSA level of 4.9-13.7 ng/ml. Regarding zonal anatomy, 5 studies reported the inter-reader agreement only for TZ ( 27 , 30 , 31 , 33 , 34 ), 2 studies reported the inter-reader agreement both for TZ and PZ ( 24 , 32 ), 4 studies reported the reproducibility for the whole gland and did not differentiate location ( 25 , 26 , 28 , 35 ), only 1 study reported the inter-reader agreement merely on PZ lesions ( 29 ). In 4 studies the MRI images were interpreted by 2 radiologists ( 28 , 29 , 31 , 34 ), whereas in the remaining 8 studies the MRI images were interpreted by at least 3 radiologists.…”

“…Regarding zonal anatomy, 5 studies reported the inter-reader agreement only for TZ ( 27 , 30 , 31 , 33 , 34 ), 2 studies reported the inter-reader agreement both for TZ and PZ ( 24 , 32 ), 4 studies reported the reproducibility for the whole gland and did not differentiate location ( 25 , 26 , 28 , 35 ), only 1 study reported the inter-reader agreement merely on PZ lesions ( 29 ). In 4 studies the MRI images were interpreted by 2 radiologists ( 28 , 29 , 31 , 34 ), whereas in the remaining 8 studies the MRI images were interpreted by at least 3 radiologists. Regarding readers’ experience, 5 studies reported that the MRI images were interpreted by experienced or dedicated radiologists ( 25 , 27 , 31 , 34 , 35 ), whereas in the remaining 7 studies the images were interpreted by radiologists with varied experience (1-20 years).…”

Interreader agreement in different PI-RADS systems in multiparametric prostate magnetic resonance imaging: A head-to-head comparison between PI-RADSv2 and v2.1

“…[15] These findings were also supported for PZ lesions in the study of Bhayana et al [16] They found that interreader agreement was higher in PI-RADSv2.1 (kappa = 0.64) than PI-RADSv2 (kappa = 0.51). Unlikely, Hötker et al [17] claimed that interreader agreement was higher in the former version (Kappa = 0.57 for PI-RADSv2 and Kappa = 0.51 for PI-RADSv2.1). But the difference of experience between the readers was higher in this study.…”

Biparametric Magnetic Resonance Imaging‐Derived Nomogram to Detect Clinically Significant Prostate Cancer by Targeted Biopsy for Index Lesion

“…Therefore, multi-institutional studies with image interpretation data of multiple radiologists are needed to confirm the generalizability of our results. Recent studies have reported that the interreader agreement was moderate or good (kappa, 0.51-0.64) for interpreting PI-RADSv2.1 [37][38][39] and excellent (concordance correlation coefficient, >0.80) for ADCR, 32 respectively. External validation studies are needed to test the feasibility of the nomogram despite some variabilities in MRI interpretation.…”