Magnetic resonance imaging identifies early effects of sunitinib treatment in human melanoma xenografts

Background: antiangiogenic treatment may change the tumor microenvironment and hence influence the effect of conventional therapies. the potential of diffusion weighted magnetic resonance imaging (dw-mri) and dynamic contrast enhanced mri (dce-mri) in assessing microenvironmental effects of sunitinib treatment was investigated in this preclinical study. methods. sunitinib-treated and untreated a-07 tumors were subjected to dw-mri and dce-mri,and parametric images of adc and k §ssup§trans§esup§ were produced. microvascular density,hypoxic fraction,and necrotic fraction were assessed from immunohistochemical preparations,and tumor interstitial fluid pressure (ifp) was assessed with probe measurement. results: sunitinib-treated tumors showed reduced microvascular density,increased hypoxic fraction,increased necrotic fraction,increased adc,and reduced k §ssup§trans§ esup§,but did not differ from untreated tumors in growth rate and ifp. conclusions: sunitinib treatment affected the tumor microenvironment without affecting tumor size. dw-mri and dce-mri were sensitive to the sunitinib-induced changes in the tumor microenvironment. © 2013 gaustad et al.; licensee biomed central ltd.