Imaging prostate cancer (PCa) with [^99m Tc(CO)₃ ]finasteride dithiocarbamate

This investigation aimed to modify finasteride (1) to finasteride dithiocarbamate (2) for subsequent synthesis of the rhenium analogue (3) and [^99m Tc]tricarbonyl complexes (4), to assess its prostate cancer (PCa) targeting potential in a rat model. To validate the identity of (4), reference (3) has been synthesized by using fac-[Net₄ ]₂ [ReBr₃ (CO)₃ ] precursor and characterized by ¹ H-NMR, ¹³ C-NMR, ESI-MS, and elemental analysis. The analogue (4) was synthesized by using fac-[^99m Tc(H₂ O)₃ (CO)₃ ]⁺ precursor, and its structure was confirmed by comparative HPLC by using (3) as a reference. Further, the suitability of (4) as a PCa imaging agent was investigated in vitro and in vivo. At room temperature, (4) had ≥99% radiochemical purity and remained ≥84% stable in serum. In preclinical studies, biodistribution of (4) in histopathologically established rat model showed adequately high in vivo uptake in the prostate attracting the possibility of using it for noninvasive imaging of PCa.