Imaging Tumor Xenografts Using Radiolabeled Antibodies

Non-invasive, molecular imaging of malignancies using radiolabeled antibodies as tracers is an emerging field that can offer information on staging and response to therapy. Protein engineering approaches enable fully human antibodies to be generated against any novel target and reformatted for optimal properties for positron emission tomography imaging (immunoPET). This chapter describes the steps required for imaging tumor xenografts in vivo in preclinical models with engineered antibody fragments. Two radiolabeling approaches, iodination and radiometal labeling, are described in detail including the conjugation of the radiometal chelator, DOTA, to the protein. Protocols for the assessment of the biological function of the protein after radiolabeling as well as establishment of tumor xenografts have also been included.