Preclinical evaluation of (99m)Tc labeled gefitinib as a potential scintigraphic probe for the detection of tumors expressing epidermal growth factor receptors.

In the present study, we successfully radiolabeled gefitinib with (99m)Tc by direct labeling method. The radio-ligand had radiolabeling efficiency of >95.0% and in vitro stability of >80.0% at 24h. The radiotracer cleared from blood bi-exponentially. Animal organ biodistribution data indicated hepato-renal excretion of the radiotracer. Scintigraphy carried out in tumor bearing mice (induced by EGFR expressing EAT cell lines) demonstrated that the radiotracer accumulated in the tumor site with T/NT ratio of 3.3±0.2 at 1h.