title: Development of a preclinical211Rn/211At generator system for targeted alpha therapy research with211At.
abstract: BACKGROUND
  The availability of211At for targeted alpha therapy research can be increased by the211Rn/211At generator system, whereby211At is produced by211Rn electron capture decay. This study demonstrated the feasibility of using generator-produced211At to label monoclonal antibody (BC8, anti-human CD45) for preclinical use, following isolation from the207Po contamination also produced by these generators (by211Rn α-decay).
  
  
  METHODS
  211Rn was produced by211Fr electron capture decay following mass separated ion beam implantation and chemically isolated in liquid alkane hydrocarbon (dodecane).211At produced by the resulting211Rn source was extracted in strong base (2N NaOH) and purified by granular Te columns. BC8-B10 (antibody conjugated with closo-decaborate(2-)) was labeled with generator-produced211At and purified by PD-10 columns.
  
  
  RESULTS
  Aqueous solutions extracted from the generator were found to contain211At and207Po, isolated from211Rn. High radionuclidic purity was obtained for211At eluted from Te columns, from which BC8-B10 monoclonal antibody was successfully labeled. If not removed,207Po was found to significantly contaminate the final211At-BC8-B10 product. High yield efficiencies (decay-corrected, n=3) were achieved for211At extraction from the generator (86%±7%), Te column purification (70%±10%), and antibody labeling (76%±2%).
  
  
  CONCLUSIONS
  The experimental211Rn/211At generator was shown to be well-suited for preclinical211At-based research.
  
  
  CONCLUSIONS
  We believe that these experiments have furthered the knowledge-base for expanding accessibility to211At using the211Rn/211At generator system.
  
  
  CONCLUSIONS
  As established by this work, the211Rn/211At generator has the capability of facilitating preclinical evaluations of211At-based therapies.
authors.affiliation: TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada; Department of Physics and Astronomy, University of Victoria, 3800 Finnerty Road, Victoria, British Columbia V8P 5C2, Canada. Electronic address: jcrawford@triumf.ca.
authors.forename: Jason R
authors.initials: JR
authors.lastname: Crawford
authors.affiliation: TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada.
authors.forename: Hua
authors.initials: H
authors.lastname: Yang
authors.affiliation: TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada.
authors.forename: Peter
authors.initials: P
authors.lastname: Kunz
authors.affiliation: Department of Radiation Oncology, University of Washington (Box 355016), 616 N.E. Northlake Place, Seattle, WA 98105, USA.
authors.forename: D Scott
authors.initials: DS
authors.lastname: Wilbur
authors.affiliation: TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada.
authors.forename: Paul
authors.initials: P
authors.lastname: Schaffer
authors.affiliation: TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada; Department of Physics and Astronomy, University of Victoria, 3800 Finnerty Road, Victoria, British Columbia V8P 5C2, Canada.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Ruth
mesh_terms: D000512:Alpha Particles / Q000627:therapeutic use*; D001246:Astatine / Q000737:chemistry* / Q000302:isolation & purification / Q000627:therapeutic use*; D018796:Immunoconjugates / Q000627:therapeutic use; D007553:Isotope Labeling; D011854:Radiochemistry / Q000295:instrumentation*; D011886:Radon / Q000737:chemistry*
chemical_list: D018796:Immunoconjugates; D011886:Radon; D001246:Astatine
keywords: Antibody labeling; Astatine-211, radon-211; Generator system; Radioisotope production; Targeted alpha therapy