Preclinical SPECT-MRI; in vivo radiopeptide biodistribution studies

From our results we found that tumor vascular perfusion/permeability characteristics can play a significant role in the delivery and availability of radiopeptides in vivo. In areas of tumor tissue lacking sufficient functional vessels we found only low radiopeptide uptake, even if receptor density was high. During PRRT this would implicate that tumor areas with low perfusion characteristics might not receive an effective treatment dose. Using DCE-MRI it is possible to determine local vascular functionality and to monitor changes in vascular function during and after therapy; this information might be used to optimize administration of next treatment cycles at optimal time points regarding tumor vessel functionality in patient studies as well.