The Auger-electron emitter165Er: excitation function of the165Ho(p,n)165Er process

Abstract

AbstractThe lanthanide isotope165Er decays by electron capture without any accompanying gamma radiation, which makes it an ideal radionuclide for Auger electron therapy. The chemical properties of erbium with regard to labelling of bio-conjugates are virtually identical to those of radio-yttrium. We measured the excitation function of the165Ho(p,n)165Er reaction and obtained a maximum cross section of 166±20 mb at 11.1±0.5 MeV proton energy. Our findings indicate that165Er can be produced at any small-sized cyclotron in quantities suitable for biomedical applications. The thick target yield at Ep=15 MeV is 55 MBq/μA h. A mass separated sample of the nuclide pair160Er/160Ho was used as model to demonstrate that the separation of the165Er from the target matrix material Ho can be achieved by cation-exchange chromatography using Aminex A5 resin and α-HIBA as eluent in about 1 hour.