Abstract #3251

van Beers B, Michoux n

DCE-MRI is increasingly used for non-invasive imaging the tumour microcirculation and monitoring the action of antiangiogenic agents. In practice, the vascular parameters potentially usable in clinics, displayed an unequal sensitivity to the contrast agent and pharmacokinetics model that are used. Recently, the volume transfer constant Ktrans was recommended as primary end-point, although it reflects a combined measurement of the blood flow and permeability in tumors. Investigating three agents and three models, we reassess which parameter should be measured. It is concluded that permeability differences are better assessed by measuring the volume of extravascular extracellular space rather than Ktrans.