Tc-99m direct radiolabeling of monoclonal antibody ior egf/r3: quality control and image studies in mice

Monoclonal antibodies (Mabs) have been useful for immunoscintigraphic applications in clinical diagnosis since they were introduced in the practice of nuclear medicine. The ior egf/r3 (Centis, Cuba) is a murine monoclonal antibody against epidermal growth factor receptor (EGF-R) and has been widely used in the radioimmunodiagnosis of tumors of epithelial origin. Labeled with 99mTc, its main application in Nuclear Medicine is the follow up, detection and evaluation of tumor recurrences. The objective of this work is to describe the preparation of a lyophilized formulation (kit) for radiolabeling the Mab ior egf/r3 with 99mTc for immunoscintigraphic applications. Radiolabeling efficiency, effects on immunoreactivity, image studies and stability of the formulation are reported. The study demonstrated that the kit formulation can be labeled with 99mTc at high yields and can be used to visualize in vivo human tumors of epithelial origin by immunoscintigraphy studies