Role of semi-quantitative dynamic contrast-enhanced MR imaging in characterization and grading of prostate cancer

Abstract

Objective: The study retrospectively assessed the diagnostic value of semi-quantitative dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) in characterization and grading of prostate cancer, with correlation to histopathological analysis.

Materials and methods: 161 consecutive patients with prostate cancer underwent DCE MRI. 430 lesions, including 200 cancers with Gleason grade (GG) of 6 (n=25), 7 (n=112) and 8 or higher (n=63); 80 benign hyperplasia; and 150 healthy tissues were assessed using a histology-MRI correlation. Time-intensity curve types between two radiologists and kinetic parameters (C_peak, time to peak, wash-in and wash-out) were compared in the different tissue types and GGs. Receiver operating characteristic curve analysis was performed to assess for each parameter to differentiate cancer from benign hyperplasia or healthy tissue, and GG 8 or higher from GG 6 or 7.

Results: Type 2 was the prevalent assigned curve type. Inter-radiologist agreement for the curve types was excellent. Cancer and GG 8 or higher significantly showed a higher C_peak and faster wash-in compared to healthy tissue and GG 6. Only wash-in significantly differentiated cancer from healthy tissue, and GG 8 or higher from GG 6, having an area under the curve (AUC) of 0.755 and 0.815 respectively. Wash-in for the combined parameters revealed AUCs of 0.791 and 0.839 in two (C_peak) parameters, and AUCs of 0.862 and 0.891 in three (C_peak and wash-out) parameters.

Conclusion: Semi-quantitative parameters can differentiate cancer from benign hyperplasia and healthy tissue. Wash-in is the most accurate differentiation parameter of cancer foci and GG 8 or higher.

Keywords: Dynamic contrast-enhanced MRI; Prostate cancer; Semi-quantitative parameters.