Kim Anne Radermacher1, Sbastien Boutry2, Isabelle Mahieu2, Sophie Laurent2, Luce Vander Elst2, Caroline Bouzin3, Julie Magat1, Vincent Grgoire4, Olivier Feron3, Robert N. Muller2, Bndicte F. Jordan1, Bernard Gallez1
1Biomedical Magnetic Resonance Unit, Catholic University of Louvain, Bruxelles, Belgium; 2NMR and Molecular Imaging Laboratory, University of Mons, Mons, Belgium; 3Unit of Pharmacology and Therapeutics, Catholic University of Louvain, Bruxelles, Belgium; 4Center for Molecular Imaging and Experimental Radiotherapy, Catholic University of Louvain, Bruxelles, Belgium
The aim was to develop a molecular marker for non invasive monitoring of tumor cell death as a response to treatment. The phosphatidylserine-targeted peptide E3 was coupled to ultrasmall particles of iron oxide (USPIO). The USPIO concentration was evaluated in irradiated and untreated tumors by EPR and MRI in vivo. We also compared USPIO-E3 accumulation in three different tumor models presenting different degrees of radiosensitivity (fibrosarcoma is less radiosensitive than hepatocarcinoma which is less radiosensitive than lymphoma). The major finding of the present investigation is that USPIO-E3 allows the sensitive detection of tumor cell death after cytotoxic treatment.