Although sound methods exist to derive physical perfusion parameters like regional blood volume, blood flow and permeability from dynamic contrast enhanced studies, we found that these methods require a higher temporal resolution than currently is practically achievable for volumetric CT with full nodule coverage. Yet, the elaborated average enhancement color overlays allow for easy, semi-quantitative evaluation of therapy response by radiologists. The methodology developed in this study provides hence a useful tool that can be used in clinical practice to evaluate tumour response as a viable alternative to the less prevalent PET imaging modality.