Original articleGenitourinary imagingDetection of locally radio-recurrent prostate cancer at multiparametric MRI: Can dynamic contrast-enhanced imaging be omitted?

ObjectiveThe goal of this study was to assess the added value of dynamic contrast-enhanced (DCE) imaging in detecting locally radio-recurrent prostate cancer using multiparametric magnetic resonance imaging (mpMRI) at 3 Tesla (T).Materials and methodsWe retrospectively analyzed 45 patients with rising prostate-specific antigen level after prostate radiotherapy who underwent mpMRI [T2-weighted (T2w), diffusion-weighted (Dw) and DCE imaging] at 3 T before prostate biopsy. Four readers assigned a 5-level Likert score of cancer likelihood in 8 prostate sectors (6 sextants, 2 seminal vesicles) on T2w + Dw and T2w + Dw + DCE images. Biopsy results were used as the standard of reference.ResultsT2w + Dw and T2w + Dw + DCE imaging had similar areas under the receiver operating characteristic curves on per-sector (0.87-0.89 vs. 0.87-0.89; P = 0.19-0.78) and per-lobe (0.82-0.94 vs. 0.80-0.91; P = 0.21-0.84) analysis. Using a Likert score ≥ 2/5 for diagnosis threshold, T2w + Dw + DCE imaging showed non-significantly higher sensitivities on per-sector (0.56-0.72 vs. 0.52-0.73, P = 0.34-0.69) and per-lobe (0.80-0.90 vs. 0.73-0.88; P = 0.63-0.99) analysis. It also showed non-significantly lower specificities on per-sector (0.74-0.89 vs. 0.82-0.89; P = 0.09-0.99) and per-lobe (0.48-0.81 vs. 0.61-0.84; P = 0.10-0.99) analysis. Weighted kappa values were respectively 0.57-0.70 and 0.55-0.66 for T2w + Dw and T2w + Dw + DCE imaging at the sector level, and 0.66-0.83 and 0.58-0.85 at the lobe level.ConclusionThe use of DCE MR imaging tends to increase sensitivity and decrease specificity for all readers, but the differences are not significant.