Production of 230U/226Th for targeted alpha therapy via proton irradiation of 231Pa

Anal Chem. 2008 Nov 15;80(22):8763-70. doi: 10.1021/ac801304c. Epub 2008 Oct 17.

Abstract

(230)U and its daughter nuclide (226)Th are novel therapeutic nuclides for application in targeted alpha-therapy of cancer. We have investigated the feasibility of producing (230)U/(226)Th via proton irradiation of (231)Pa according to the reaction (231)Pa(p,2n)(230)U. The experimental excitation function for this reaction is reported for the first time. Cross sections were measured using thin targets of (231)Pa prepared by electrodeposition and (230)U yields were analyzed using alpha-spectrometry. Beam parameters (energy and intensity) were determined both by calculation using a mathematical model based on measured beam orbits and beam current integrator and by parallel monitor reactions on copper foils using high-resolution gamma-spectrometry and IAEA recommended cross-section data. The measured cross sections are in good agreement with model calculations using the EMPIRE-II code and are sufficiently high for the production of (230)U/(226)Th in clinically relevant amounts. A highly effective separation process was developed to isolate clinical grade (230)U from irradiated protactinium oxide targets. Product purity was assessed using alpha- and gamma-spectrometry as well as ICPMS.

MeSH terms

  • Alpha Particles / therapeutic use*
  • Chemical Precipitation
  • Chromatography
  • Electroplating
  • Oxides / chemistry
  • Protactinium / chemistry*
  • Protons*
  • Thorium / chemistry*
  • Thorium / therapeutic use
  • Uranium / chemistry*
  • Uranium / isolation & purification
  • Uranium / therapeutic use

Substances

  • Oxides
  • Protons
  • Protactinium
  • Uranium
  • Thorium