Experimental studies on imaging of infected site with 99mTc-labeled ciprofloxacin in mice

Background Bacterial infection can pose a substantial diagnostic dilemma. Tc-99m-labeled ciprofloxacin (CPF) was developed as a biologically active radiopharmaceutical to diagnose infection. In the present research, we studied the biodistribution and imaging properties of infection tracer Tc-99m-CPF in a mouse model of infection. Methods CPF was labeled with Tc-99m and the radiochemical purity and labeling rate were measured. A mouse model of infection was established. We then determined the biodistribution of Tc-99m-CPF and conducted the whole body scintigraphy of the animal model. Results Tc-99m-Ciprotech was stable for at least 6 hours at room temperature. The labeling rate of CPF by Tc-99m was over 90%. Clearance of radioactivity mainly occurred in the liver and kidney, and the clearance from blood was rapid. Both biodistribution and imaging results showed higher uptake of Tc-99m-CPF at sites of infection. The infectious tissue/normal tissue ratio peak was 4.30 at 4 hours after injection. Conclusions Tc-99m-CPF is a sensitive radiopharmaceutical for scintigraphy of infectious lesions and it is easy to prepare. Chin Med J 2009;122(16):1907-1909