The performance of PI-RADSv2 and quantitative apparent diffusion coefficient for predicting confirmatory prostate biopsy findings in patients considered for active surveillance of prostate cancer

Abstract

Purpose To assess the performance of the updated Prostate Imaging Reporting and Data System (PI-RADSv2) and the Apparent Diffusion Coefficient (ADC) for predicting confirmatory biopsy results in patients considered for active surveillance of prostate cancer (PCA). Methods IRB-approved, retrospective study of 371-consecutive men with clinically low-risk PCA (initial biopsy Gleason score≤6, prostate-specific-antigen<10ng/ml, clinical stage≤T2a) who underwent 3T-prostate MRI before confirmatory biopsy. Two independent radiologists recorded the PI-RADSv2 scores and measured the corresponding ADC values in each patient. A composite score was generated to assess the performance of combining PI-RADSv2+ADC. Results PCA was upgraded on confirmatory biopsy in 107/371 (29%) patients. Inter-reader agreement was substantial (PI-RADSv2: k=0.73; 95%CI [0.66–0.80]; ADC: r=0.74; 95%CI [0.69–0.79]). Accuracies, sensitivities, specificities, positive, negative predicted values of PI-RADSv2 were 85%, 89%, 83%, 68%, 95% and 78%, 82%, 76%, 58%, 91% for ADC. PI-RADSv2 accuracy was significantly higher than that of ADC for predicting biopsy upgrade (p=0.014). The combined PI-RADSv2+ADC composite score did not perform better than PI-RADSv2 alone. Obviating biopsy in patients with PI-RADSv2 score ≤3 would have missed Gleason Score upgrade in 12/232 (5%) of patients. Conclusion PI-RADSv2 was superior to ADC measurements for predicting PCA upgrading on confirmatory biopsy.

Is magnetic resonance imaging‐targeted biopsy a useful addition to systematic confirmatory biopsy in men on active surveillance for low‐risk prostate cancer? A systematic review and meta‐analysis

“…Studies on MRI and AS were excluded if MRI had previously been used (initial biopsies or previous negative biopsies) , if data on negative prostate MRI was excluded , if Gleason score 3 + 4 at initial TRUS biopsy was also included in the AS cohort , if sampled lesions with suspicion score of ‘2’ on MRI could not be excluded from the results , when MRI suspicion scores (Likert or PI‐RADS) were dichotomised as positive to a score ≥4 instead of a score ≥3 , if template biopsies (>20 cores) was used as the reference test , if data extraction to 2 × 2 contingency tables was not possible , if a transperineal biopsy approach , or unclear definition of index test was used . We excluded double publications .…”

Prostate Cancer Imaging and Biomarkers Guiding Safe Selection of Active Surveillance

“…Over the past 10 years, the PIRADS has become an increasingly useful tool in both the initial diagnostic setting and for monitoring patients on AS ( 25 – 27 ). The PIRADS system is a five-point Likert scale applied to a suspicious lesion on MRI.…”

“…More recently, a proposed PIRADS version 2 (PIRADSv2) was developed to reflect increasingly complex MRI interpretation with the application of multiple sequences such as DWI and dynamic contrast enhancement for interpretation of a single lesion ( 27 , 29 , 33 ). Validation studies comparing its utility to the original PIRADS algorithm are currently underway.…”

“…Validation studies comparing its utility to the original PIRADS algorithm are currently underway. However, early results indicate significant PCa may be overlooked as often as 5% of the time when using PIRADSv2 ≥3 as a cutoff ( 27 ). Furthermore, there is concern that the PIRADS algorithm may inaccurately characterize benign central zone (CZ) lesions.…”

MRI findings guiding selection of active surveillance for prostate cancer: a review of emerging evidence

“…Over the past ten years, the Prostate Imaging Reporting and Data System (PIRADS) has become an increasingly useful tool for evaluating suspicious prostatic neoplasms ( 30 - 32 ). Suspicious lesions are rated on a five-point Likert scale with a score of 5 being the most concerning for a malignant tumor ( 33 , 34 ).…”