Complex Compounds of Rhenium-188 and Gallium-68 Radionuclides and Their Behavior in the Organism of Laboratory Animals

Abstract

This paper concerns the study of pharmacokinetic properties of rhenium-188 and gallium-68 bound to a ligand based on tetraphosphonic acid (¹⁸⁸ Re,⁶⁸ Ga-EDTMP). The pharmacokinetics of ¹⁸⁸ Re,⁶⁸ Ga-EDTMP is studied using outbred rats after intravenous injection of the preparation; the results are compared with the properties of ¹⁸⁸ Re-EDTMP and ⁶⁸ Ga-EDTMP. Rapid and selective activity accumulation in bone tissue is observed. The peak specific contents of ⁶⁸ Ga and ¹⁸⁸ Re in the femoral bone are 6.85%/g and 2.76%/g, respectively. Throughout the study, the activity of radionuclides in bone tissue was higher than in blood and most soft tissue organs. ¹⁸⁸ Re,⁶⁸ Ga-EDTMP was excreted via the urinary tract. Increased activity is recorded in the thyroid gland. Other organs and tissues are characterized by low contents of the preparation. After intravenous injection of ¹⁸⁸ Re-EDTMP and ⁶⁸ Ga-EDTMP, the activity of ¹⁸⁸ Re and ⁶⁸ Ga is lower in comparison with ¹⁸⁸ Re,⁶⁸ Ga-EDTMP. Thus,¹⁸⁸ Re,⁶⁸ Ga-EDTMP is a promising preparation for theranostics of bone metastases.