Abstract #0766

Taylor N, Stirling J, Padhani A, Leach M, d'Arcy J, Collins D, Rustin G, White D, Lee C, Tang A, Koh D, Knowles B, Walker-Samuel S, Wallace T, Miaux Y, Suhy J, Guermazi A

The measurement of test-retest variability is integral to trial design of phase I antiangiogenesis and angiolytic drugs where dynamic MRI (DCE-MRI) is used to evaluate the effect of drug on tumour vasculature. Knowing kinetic parameter reproducibility enables the identification genuine pharmoacodynamic effects and this information can then be used to identify a biologically active dose. In this study we compare single and multiple centres DCE-MRI studies with the aim of identifying the change in Ktrans that would be significant for a single patient and for typical Phase I dosing cohort sizes of 3 and 6 patients.