False positives in PIRADS (V2) 3, 4, and 5 lesions: relationship with reader experience and zonal location

Abstract

Purpose To investigate the effect of reader experience and zonal location on the occurrence of false positives (FPs) in PIRADS (V2) 3, 4, and 5 lesions on multiparametric (MP)-MRI of the prostate. Materials and methods This retrospective study included 139 patients who had consecutively undergone an MP-MRI of the prostate in combination with a transrectal ultrasound MRI fusion-guided biopsy between 2014 and 2017. MRI exams were prospectively read by a group of inexperienced radiologists (cohort 1; 54 patients) and an experienced radiologist (cohort 2; 85 patients). Multivariable logistic regression analysis was performed to determine the association of experience of the radiologist and zonal location with a FP reading. FP rates were compared between readings by inexperienced and experienced radiologists according to zonal location, using Chi-square (χ 2) tests. Results A total of 168 lesions in 139 patients were detected. Median patient age was 68 years (Interquartile range (IQR) 62.5-73), and median PSA was 10.9 ng/mL (IQR 7.6-15.9) for the entire patient cohort. According to multivariable logistic regression, inexperience of the radiologist was significantly (P = 0.044, odds ratio 1.927, 95% confidence interval [CI] 1.017-3.651) and independently associated with a FP reading, while zonal location was not (P = 0.202, odds ratio 1.444, 95% CI 0.820-2.539). In the transition zone (TZ), the FP rate of the inexperienced radiologists 59% (17/29) was significantly higher (χ 2 P = 0.033) than that of the experienced radiologist 33% (13/40). Conclusion Inexperience of the radiologist is significantly and independently associated with a FP reading, while zonal location is not. Inexperienced radiologists have a significantly higher FP rate in the TZ.

Prostate Imaging-Reporting and Data System: Comparison of the Diagnostic Performance between Version 2.0 and 2.1 for Prostatic Peripheral Zone

“…Furthermore, mpMRI can be incorporated into the practical pathway and guide the decision regarding active surveillance [ 4 ]. However, the limited PPV and CDR of PI-RADSv2.0 for csPCa was associated with overestimation, resulting in the risk of unwarranted targeted biopsies [ 5 7 17 ].…”

Editorial Comment from Dr Shiota to Magnetic resonance imaging/transrectal ultrasonography fusion targeted prostate biopsy finds more significant prostate cancer in biopsy‐naïve Japanese men compared with the standard biopsy

“…The authors indicated that the dominant cancer location in the peripheral zone might explain the differential cancer detection rates by zone. Additionally, in this study, the lower PI‐RADS score in the TZ and central zone could have contributed to the lower cancer detection rate in these zones . Intriguingly, the false positive rate was higher in the TZ, especially among inexperienced radiologists, indicating that foci in the TZ can easily be overdiagnosed as suspected cancer .…”

“…Additionally, in this study, the lower PI‐RADS score in the TZ and central zone could have contributed to the lower cancer detection rate in these zones . Intriguingly, the false positive rate was higher in the TZ, especially among inexperienced radiologists, indicating that foci in the TZ can easily be overdiagnosed as suspected cancer . The false positive rate in the TZ by MRI might therefore be improved as radiologists’ experience increases.…”

“…A recent study showed that the cancer detection rate was lower in the transition zone (TZ) and central zone than in the peripheral zone . The authors indicated that the dominant cancer location in the peripheral zone might explain the differential cancer detection rates by zone.…”

External validation of a prostate cancer nomogram on magnetic resonance/transrectal ultrasound fusion biopsy in men with prior negative systematic biopsy

“…They also showed that zonal location was not significantly associated with false-positive results. 20 Truong et al used datasets from two different centres (the University of Rochester Medical Center [URMC] and the University of Alabama at Birmingham [UAB]) in their multicentre study. 12 The final nomogram (URMC + UAB) was created by combining the datasets of both centres, and we used that for comparative analysis.…”