Preparation of99mTc-Clomiphene Citrate as a Novel Agent for Breast Cancer Imaging

The aim of this work was to develop a novel 99m Tc-labelled derivative based on triphenylethylene for breast cancer imaging. 99m Tc-Clomiphene was obtained with a radiochemical yield of 94.4% by adding 99m Tc to 1.5 mg Clomiphene citrate in the presence of 10  μ g SnCl 2 at pH 7. The optimization of the labeling yield of Clomiphene citrate, with 99m Tc, is described. The reaction parameters that affect the labeling yield were studied to optimize the labeling conditions. Radiochemical purity of the final product has been verified by means of paper chromatography and paper electrophoresis. Ehrlich Ascites Carcinoma (EAC) as a model of breast cancer cells was injected intraperitoneally (IP) to produce ascites and intramuscularly (IM) to produce solid tumor. Biodistribution study was carried out by the injecting solution of 99m Tc-Clomiphene in normal and tumor bearing mice. The uptake in ascites was over 12.5 % injected dose per gram tissue body weight, at 1hr after injection and above 12% in solid tumor. The T/NT value for 99m Tc-Clomiphene complex was found to be 5.5 ± 0.4 which was higher than that of the commercially available 99m Tc-MIBI. This data revealed the localization of tracer in tumor tissue with high percent sufficient to use 99m Tc-Clomiphene as a promising tool for the diagnosis of breast cancer.