title: Holmium-166-DTPA as a liquid source for endovascular brachytherapy.
abstract: Liquid radiation sources with beta emitters have advantages of accurate positioning and uniform dose distribution to the vessel walls to prevent the restenosis of coronary artery. As a liquid radiation source, 166Ho-DTPA was prepared and evaluated its in-vivo pharmacokinetic behavior through animal studies.166Ho-DTPA was prepared by simple mixing the Holmium with DTPA at room temperature. The radiolabelling yield was 100% when the DTPA/Holmium molar ratio was >2. Radiolabelling of 166Ho-DTPA was not dependent on the pH range of 1.7-7.5. High radiochemical stability (>98%) was maintained over a period of 6 hours even with a radioactivity ( approximately 11.1 GBq/12 mg of DTPA) stored at room temperature. Biodistribution of 166Ho-DTPA in rats and gamma camera images in rabbits showed that 166Ho-DTPA was quickly excreted via the urinary system. The average of T(max) and T(1/2) of 166Ho-DTPA in the kidneys of rabbits were 3.71 +/- 1.18 min and 9.15 +/- 3.15 min. 166Ho-DTPA is a potential liquid radiation source for radiation brachytherapy to prevent the restenosis of the coronary artery using a liquid-filled balloon.
authors.affiliation: RI and Radiation Application Team, Korea Atomic Energy Research Institute, 150 Dukjin-dong, Yuseong-gu, 305-353 Daejeon, Republic of South Korea.
authors.forename: Young-Don
authors.initials: YD
authors.lastname: Hong
authors.forename: Kyung-Bae
authors.initials: KB
authors.lastname: Park
authors.forename: Beom-Su
authors.initials: BS
authors.lastname: Jang
authors.forename: Sun-Ju
authors.initials: SJ
authors.lastname: Choi
authors.forename: Sang-Moo
authors.initials: SM
authors.lastname: Choi
authors.forename: Young-Mi
authors.initials: YM
authors.lastname: Kim
mesh_terms: D000818:Animals; D001918:Brachytherapy / Q000295:instrumentation* / Q000379:methods; D006695:Holmium / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics* / Q000627:therapeutic use; D007275:Injections, Intravenous; D007553:Isotope Labeling / Q000379:methods*; D008297:Male; D008657:Metabolic Clearance Rate; D004369:Pentetic Acid / Q000008:administration & dosage / Q000138:chemical synthesis / Q000493:pharmacokinetics* / Q000627:therapeutic use; D011817:Rabbits; D011868:Radioisotopes / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics / Q000627:therapeutic use; D019275:Radiopharmaceuticals / Q000008:administration & dosage / Q000138:chemical synthesis / Q000493:pharmacokinetics; D051381:Rats; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012996:Solutions / Q000138:chemical synthesis / Q000493:pharmacokinetics / Q000627:therapeutic use; D014018:Tissue Distribution; D014652:Vascular Diseases / Q000532:radiotherapy; D014915:Whole-Body Counting
chemical_list: D011868:Radioisotopes; D019275:Radiopharmaceuticals; D012996:Solutions; D004369:Pentetic Acid; D006695:Holmium