Optimizing [99mTc]Tc-Tamsulosin for Enhanced Tumor Detection: A Comprehensive Approach from Preparation to In Vivo Evaluation

Purpose: To investigate the potential of Tamsulosin hydrochloride, a selective α1-adrenoceptor antagonist, as a tumor-targeting ligand when labeled with Technetium-99 m [⁹⁹ᵐTc] for use as a novel radiopharmaceutical. This study aims to develop and evaluate the [⁹⁹ᵐTc]Tc-Tamsulosin complex for enhanced tumor imaging and improved diagnostic accuracy in oncology. Methods: , with the mixture incubated at room temperature (25°C) for 30 min. Radiochemical yield and in vitro stability were assessed via TLC, and purification was performed through electrophoresis and high-performance liquid chromatography (HPLC), followed by in vivo evaluation studies in tumor-bearing mice versus normal mice. Results: The [⁹⁹ᵐTc]Tc-Tamsulosin complex achieved a radiochemical purity of 97.5 ± 0.12% and maintained in vitro stability in serum and PBS above 87 ± 0.22% after 24 h. In vivo evaluation revealed peak tumor uptake (T) of 5.2 ± 0.02% ID/g and normal muscle (NT) uptake of 0.98 ± 0.01% ID/g at 2 h post-injection, with a target-to-non-target ratio of 5.3. Renal clearance was prominent, with kidney uptake of 16 ± 0.24% ID/g and urinary excretion reaching 25 ± 1.37% ID/g at 3 h. Conclusion: The [⁹⁹ᵐTc]Tc-Tamsulosin complex demonstrates high radiolabeling efficiency, stability, and selective tumor accumulation, supporting its potential as a promising radiopharmaceutical for accurate tumor imaging. These findings highlight its value in advancing nuclear medicine oncology diagnosis.