Journal of Clinical Medicine
External Validation of MRI-Based Prostate Cancer Risk Calculators in a Contemporary Pre-Biopsy mpMRI Cohort
By Hubert Griessner, Sarah K. Luck, Julia K. Peters and 6 others.
Abstract
Background
Multiparametric MRI (mpMRI)-integrated risk calculators may improve individualized prediction of clinically significant prostate cancer (csPCa) before biopsy. We externally validated and directly compared the MRI-based Radtke and Alberts risk calculators (Radtke-RC and Alberts-RC) in a contemporary MRI-selected biopsy cohort, assessing discrimination, calibration, and clinical utility.
Methods
Consecutive patients undergoing pre-biopsy mpMRI followed by combined MRI-targeted and systematic biopsy were retrospectively identified. The primary endpoint was csPCa, defined as ISUP Grade Group ≥ 2. Discrimination was assessed using receiver operating characteristic analysis, calibration using observed-to-expected (O:E) ratios, calibration-in-the-large (slope fixed at 1), calibration slopes, and calibration plots, and clinical utility using decision curve analysis. Radtke-RC validation was restricted to biopsy-naïve patients, while head-to-head comparisons were restricted to biopsy-naïve patients evaluable for both calculators. Threshold probabilities of 12%, 20%, and 30% were examined, with bootstrap confidence intervals for incremental net benefit.