Preparation and biodistribution of a 99mTc tricarbonyl complex with deoxyglucose dithiocarbamate as a tumor imaging agent for SPECT

The deoxyglucose dithiocarbamate (DGDTC) was successfully labeled with the ^99mTc(CO)₃ core to provide the corresponding ^99mTc(CO)₃–DGDTC complex in good yields. The radiochemical purity of the ^99mTc(CO)₃–DGDTC complex was over 90%, as measured by high performance liquid chromatography (HPLC). The complex possessed good stability in saline at room temperature and in mouse plasma at 37 °C. Its partition coefficient result indicated that it was a hydrophilic complex. The electrophoresis results showed the complex was neutral. The biodistribution of ^99mTc(CO)₃–DGDTC in mice bearing S 180 tumor showed that the complex clearly accumulated in tumor, exhibiting high tumor/blood and tumor/muscle ratios and good tumor retention. Single photon emission computed tomography (SPECT) image studies showed there was a visible uptake in tumor sites, suggesting ^99mTc(CO)₃–DGDTC could be considered as a potential tumor imaging agent.