title: An assessment of radionuclidic impurities of (210)Po produced via neutron irradiation of (209)Bi for use in targeted alpha-particle radiotherapy.
abstract: Radionuclidic impurities of (210)Po prepared by neutron irradiation of (209)Bi via the (209)Bi(n,gamma)(210)Bi reaction were investigated. Following irradiation and ingrowth, a pure (210)Po solution was obtained by sublimation and dissolution. Results were obtained by liquid scintillation (LS) counting, isotope dilution alpha (alpha)-spectrometry, and high-purity germanium gamma-ray spectrometry. No alpha-emitting (3-10MeV) or gamma-emitting (30-3600keV) impurities were detected, with calculated lower limits of detection for impurities of approximately 0.01% (210)Po activity. LS spectra revealed no identifiable beta-emitting impurity. LS sources prepared using Opti-Phase 'Hi Safe' III and Opti-Fluor LS cocktails were stable over a 4-day multi-cycle counting period for (210)Po dissolved in 0.1% trifluoracetic acid (pH approximately 2, water fraction approximately 2%). The radioactivity concentration determined by LS counting was verified by isotope dilution alpha spectrometry. These results suggest that neutron irradiation of (209)Bi (followed by sublimation) can produce (210)Po in a highly pure form that is suitable for radiopharmaceutical preparations.
authors.affiliation: National Institute of Standards and Technology, Nuclear Medicine Standards Program, 100 Bureau Drive MS 8462, Gaithersburg, MD 20899, USA. michael-schultz@uiowa.edu
authors.forename: Michael K
authors.initials: MK
authors.lastname: Schultz
authors.forename: Mark P
authors.initials: MP
authors.lastname: Borgman
authors.forename: Tomika
authors.initials: T
authors.lastname: Coleman
authors.forename: Sergei
authors.initials: S
authors.lastname: Bakhlanov
authors.forename: Nikolai
authors.initials: N
authors.lastname: Marchenkov
authors.forename: Bruce R
authors.initials: BR
authors.lastname: Line
mesh_terms: D000512:Alpha Particles; D001729:Bismuth / Q000737:chemistry*; D009502:Neutrons; D011059:Polonium / Q000032:analysis* / Q000627:therapeutic use; D011868:Radioisotopes / Q000737:chemistry*; D019275:Radiopharmaceuticals / Q000032:analysis* / Q000627:therapeutic use
chemical_list: D011868:Radioisotopes; D019275:Radiopharmaceuticals; D011059:Polonium; D001729:Bismuth