Synthesis and preclinical pharmacological evaluation of 99mTc-TEDP as a novel bone imaging agent

The detection of bone metastasis in early stages requires the development of high-affinity bone imaging radio-pharmaceuticals for the improvement of the diagnostic accuracy of routine bone scanning and effective management of these medical cases. This study aimed to provide a convenient synthesis of 1-thioethylidene-I,I-disodiumphosphonate (TEDP) and an improved preparation of its Tc-99m-TEDP complex. The results showed that the radiochemical purity of Tc-99m-TEDP was found to be 95 +/- 2% and that its stability was up to 6 h. Biodistribution study showed high and long uptake of Tc-99m-TEDP in bone starting from 15 min (39 +/- 4 ID/g) to 3 h (53 +/- 2.4 ID/g) showing high affinity of Tc-99m-TEDP complex to bones. This research could introduce a novel radiopharmaceutical that could be used in scanning body bones starting from 15 min between injection of Tc-99m-TEDP and bone imaging, minimizing the burden on patients in terms of the total length of the examination and the dose of radiation absorbed and showing high specificity and efficacy in bone scintigraphy.