Purpose To explore the impact of DCE-CT as a biomarker in mRCC. ￼ Methods and Materials 12 patients with mRCC participating in a phase II trial with immunotherapy and bevacizumab and with a follow-up time of at least 2 years were included in this preliminary analysis. DCE-CT interpretation (max slope method) was performed blinded to treatment group. DCE-CT scans were performed using a Philips iCT or Brilliance 64 at baseline, 5 and 10 weeks and 6, 9, 12, 15, 18, 21 and 24 months. Perfusion (P, ml/min/100 ml), peak enhancement (PE, HU), time to peak (TTP, sec) and blood volume (BV, ml/100 g) were calculated using a Philips Extended Brilliance workstation version 4.5.2. DCE-CT parameters were correlated with the relative changes in the sums of diameters (RECIST 1.1), progression free survival (PFS) and overall survival (OS) using Wilcoxon, Man-Whitney, Kaplan Meier and Log Rank statistics, as appropriate. Results High baseline P using quartiles was correlated to improved OS (not reached vs 5.2 months (p=0.011)) and PFS (p= 0.026). Using medians, the relative change in BV between baseline and week 5 was correlated to PFS (not reached vs. 5.3 months (p=0.0009)) with larger reductions being predicative of longer survival. Relative changes in P and BV between baseline and week 10 were also correlated to OS (p=0.031 for both). Four other parameters for BV and P had p values <0.10. Conclusion DCE-CT is a potential biomarker in patients with mRCC. However, large-scale studies are needed before the method can be implemented clinically.