The primary objective of study CT 4003 is to assess the behavior of EndoTAG®-1 in the body (making a so-called pharmacokinetic profile). Therefore, the course of the drug in the body is examined, i.e. the amount and speed of the drug uptake as well as the distribution and the elimination of the drug is being investigated. Further objectives of the study are to assess the effect of EndoTAG®-1 on liver metastases concerning size and blood supply measured by imaging techniques (contrast-enhanced ultrasound and magnetic resonance imaging as well as duplex sonography) and to assess the effect on blood markers which are indicators for the destruction and neoplasm of blood vessels (so-called markers of angiogenesis).