Preparation and animal biodistribution of 166Ho labeled DOTA for possible use in intravascular radiation therapy (IVRT)

✍ Scribed by Tapas Das; Sudipta Chakraborty; Sharmila Banerjee; Grace Samuel; H. D. Sarma; Meera Venkatesh; M. R. A. Pillai

• Book ID: 102373181
• Publisher: John Wiley and Sons
• Year: 2003
• Tongue: French
• Weight: 124 KB
• Volume: 46
• Category: Article
• ISSN: 0022-2135
• DOI: 10.1002/jlcr.657

✦ Synopsis

Owing to its favorable decay characteristics (T 1=2 ¼ 27 h, E bðmaxÞ ¼ 1:85 MeV, E g ¼ 81 keV) and its availability with a specific activity of 3.7-4.4 GBq/mg from a moderate flux reactor, 166 Ho can be considered as a potential radionuclide for intravascular radiation therapy (IVRT) using liquid-filled balloons. In the present work, studies on the use of 166 Ho labeled 1,4,7,10tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) as a possible agent for IVRT for the prevention of restenosis has been initiated. 166 Ho was obtained by irradiating natural Ho 2 O 3 powder and DOTA was synthesized by a multistep procedure. The optimum protocol of radiolabeling of DOTA with 166 Ho was achieved by varying different reaction parameters. The complex was found to retain its stability for 7 days at room temperature. Bioevaluation studies carried out in Wistar rats showed that >95% of the injected activity was excreted within 3 h p.i. with almost no retention in any major organ. Both radiochemical and biological studies showed that 166 Ho labeled DOTA can be further explored as a potential agent for IVRT.