Radioactive byproducts in [ 18O]H 2O used to produce 18F for [ 18F]FDG synthesis

Abstract

Potential radioactive byproducts in [ 18O]H 2O irradiated with 9.6 MeV protons to produce 18F were analyzed theoretically and experimentally. Twenty two nuclear reaction cross sections included in the National Nuclear Data Center's (NNDC) data base were selected from the possible nuclear reactions between 9.6 MeV protons and a silver havar target. Ten radionuclides: 52Mn, 55Fe, 55Co, 56Co, 57Co, 58Co, 59Ni, 95Tc, 96Tc and 109Cd were detected experimentally in [ 18O]H 2O by using high purity germanium semiconductor detectors. The activities of the 10 radionuclides were distributed between 4 Bq and 1.2 kBq. These activities were less than the reference values given in the International Basic Safety Standards. The radionuclides derived from nuclear reactions between a silver target body and 9.6 MeV protons at a beam current 25 μA for 60 min irradiation would be exempt from restrictions for radioactive waste. The purified [ 18F]FDG prepared from 18F produced by irradiating a silver havlar target with 9.6 MeV protons was not contaminated by the radionuclides.