Dynamic contrast‐enhanced imaging in localizing local recurrence of prostate cancer after radiotherapy: Limited added value for readers of varying level of experience

Background The incremental value of dynamic contrast‐enhanced (DCE) imaging in localizing radiorecurrent prostate cancer is uncertain. Purpose To assess the added‐value of DCE imaging to the combination T2‐weighted imaging (T2W)+diffusion‐weighted imaging (DWI) in detecting locally radiorecurrent prostate cancer (PCa), by radiologists with different levels of experience. Study Type Analytic retrospective study. Population In all, 52 men with biological suspected PCa recurrence after radiotherapy were retrospectively included. Field Strength/Sequence All men underwent prostatic MRI (1.5T or 3T), including T2W, DWI, and DCE imagings, before biopsies. Assessment Two junior (6 months' experience) and two senior readers (more than 3 years' experience) independently assigned a Likert score for each prostatic sextant on T2W+DW+DCE imagings, then on T2W+DW imagings, 4 weeks later. Statistical Tests The reference standard was prostatic biopsies. For two levels of positivity of Likert score, 3/5 and 4/5, sensitivity, specificity, area under the receiver operating curve (AUC), and interreader agreement were compared. Results T2W+DWI+DCE and T2W+DWI imaging had similar AUC at lobe and sextant level (0.853–0.946 vs. 0.819–0.955, P from 0.071–0.534). Using a Likert score ≥4/5, T2W+DWI+DCE significantly improved the sensitivity for junior readers at the patient, lobe, and sextant level (40–80% vs. 22–66%, P