Objective: The goal of this study was to investigate the local tumor blood supply parameters relative tumor blood volume (rTBV) and transfer coefficient (K^trans) measurable with dynamic contrast enhanced computed tomography (DCE-CT) in patients with non-small-cell lung cancer (NSCLC) scheduled for radiation therapy (RT). Materials and methods: rTBV and K^trans were measured before RT in 31 patients with clinically inoperable NSCLC (Stages I-III), which received (n=19) or did not receive (n=12) induction chemotherapy (IChT). Possible links between rTBV and K^trans and time-to-progression (TTP), overall survival (OS) and maximum standardized uptake value (SUV_max) from fluorodeoxyglucose positron emission tomography as well as histology were analyzed. Results: NSCLC showed a wide range of rTBV and K^trans values as estimated by DCE-CT (6.4±0.6ml/100ml and 18.2±1.5ml/100ml/min correspondingly). A significant difference in rTBV values in patients with IChT (4.6±0.6ml/100ml) and without IChT (7.5±0.9ml/100ml; p=0.023), depending on the number of cycles of the IChT and the clinical stage was found. A negative correlation between rTBV and TTP was revealed only in RT patients up-staged by FDG-PET/CT from stage III to stage IV (n=7, r=-0.96, p=0.0006). An inverse correlation between K^trans and TTP (n=24, r=-0.53, p=0.008) was observed in all RT patients. No relevant correlation was detected between rTBV, K^trans and SUV_max or histologic subtypes and grading. Conclusions: Tumor blood supply parameters derived from DCE-CT are useful to characterize tumor vascularization before radiotherapy in patients with NSCLC and data on outcome prediction are supplemented.