title: Preparation and preliminary biological evaluation of a (166)Ho labeled polyazamacrocycle for possible use as an intravascular brachytherapy (IVBT) agent.
abstract: (166)Ho can be considered as a potential radionuclide for intravascular brachytherapy (IVBT) using liquid-filled balloons owing to its suitable nuclear decay characteristics. The possibility of producing (166)Ho with adequate specific activity using moderate flux reactors and natural holmium target makes it an attractive alternative of (188)Re for developing IVBT agents. Keeping in mind the high thermodynamic stability of lanthanide complexes with polyazamacrocycles, (166)Ho complex of 1,4,8,11-tetraazacyclotetradecane-1,4,8,11-tetraacetic acid (TETA) was prepared and studied for its suitability as a possible agent for IVBT. (166)Ho was produced with adequate specific activity and high radionuclidic purity by irradiating natural Ho(2)O(3) powder. TETA was synthesized by a single step procedure using cyclam as the starting material. (166)Ho-TETA complex was prepared with excellent radiochemical purity and the complex was found to retain its stability for 7 days at room temperature. Biodistribution studies carried out in Wistar rats showed major renal clearance of the injected activity with almost no retention in any of the vital organ/tissue.
authors.affiliation: Radiopharmaceuticals Division, Bhabha Atomic Research Centre, Mumbai-400085, India.
authors.forename: Sudipta
authors.initials: S
authors.lastname: Chakraborty
authors.forename: Tapas
authors.initials: T
authors.lastname: Das
authors.forename: Sharmila
authors.initials: S
authors.lastname: Banerjee
authors.forename: H D
authors.initials: HD
authors.lastname: Sarma
authors.forename: Meera
authors.initials: M
authors.lastname: Venkatesh
mesh_terms: D000818:Animals; D001918:Brachytherapy / Q000379:methods*; D002851:Chromatography, High Pressure Liquid; D004590:Electrophoresis, Paper; D006695:Holmium / Q000493:pharmacokinetics / Q000627:therapeutic use*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D009942:Organometallic Compounds / Q000493:pharmacokinetics / Q000627:therapeutic use*; D011868:Radioisotopes / Q000493:pharmacokinetics / Q000627:therapeutic use*; D051381:Rats; D017208:Rats, Wistar; D017550:Spectroscopy, Fourier Transform Infrared; D014018:Tissue Distribution
chemical_list: D009942:Organometallic Compounds; D011868:Radioisotopes; C511089:holmium 1,4,8,11-tetraazacyclotetradecane-1,4,8,11-tetraacetic acid; D006695:Holmium