In Vivo Imaging Study of Samarium-153 EDTMP in Normal Rats: Preliminary Results

In vivo imaging study in animal models is a valuable tool for determining the biodistribution of radiopharmaceuticals. The imaging study is important as it provides a preclinical data before it can be proceeded to clinical study. In this study, we evaluated a feasible protocol for animal imaging of Samarium-153 EDTMP in normal rats. 8 weeks old rat with a weight of 200 - 300 gram was used in this study. The rat was anaesthetized by using diethyl ether in an air tight chamber. The imaging study was done by using the Hamamatsu BHP6602 Gamma Camera. The image was acquired by using the Technetium-99m energy window at 140 keV, later was narrowed down to cover the energy range for Samarium-153 which was at 103 keV. Imaging was performed at a minimum of 500,000 counts in order to get the best resolution. Administration of the radiopharmaceutical was given intravenously through the rats tail vein. The imaging was done at immediately after injection, at 4 hours, 24 hours and 48 hours. Imaging results were consistent with the radiochemical purity results for the Samarium-153 EDTMP preparation. The result confirms that the experimental setup for in vivo imaging study of Samarium-153 EDTMP in rats was feasible and reliable. (author)