Abnormal morphology biases haematocrit distribution in tumour vasculature and contributes to heterogeneity in tissue oxygenation

Heterogeneity in oxygen distribution in solid tumours is recognised as a limiting factor for therapeutic efficacy. Vessel normalisation strategies, aimed at rescuing abnormal tumour vascular phenotypes and alleviating hypoxia, have become an established therapeutic strategy. However, understanding of how pathological blood vessel networks and oxygen transport are related remains limited. In this paper, we establish a causal relationship between the abnormal vasculature of tumours and their heterogeneous tissue oxygenation. We obtain average vessel lengths L and diameters d from tumour allografts of three cancer cell lines and observe a substantial reduction in the ratio λ = L /d compared to physiological conditions. Mathematical modelling reveals that small values of the measured ratio λ (i.e. λ