Cyclotron isotopes and radiopharmaceuticals

The production of carrier-free 45Ti at the BNL 60 in. cyclotron by the 45Sc(p,n) reaction is discussed. Scandium and Sc203 targets were used with a proton energy of 12.4 MeV. The radiochemical procedure for the recovery of the carrier-free 45Ti is described. It is reported that the radionuclide purity of 45Ti separated from thick targets was > 99.95 per cent , the production rate obtained for protons degraded from 12.5 to 10.5 MeV was 9.2 +- 0.2 mCi/μAh and the maximum amount of 45Ti produced for an irradiation was 81.7 mCi at end of bombardment. The production rate was increased to 17.9 +-0.2 mCi/μAh at 16.2 MeV but the level of 44Scsup(m) to be removed approached 5 per cent. The 45Ti was used for a preliminary evaluation of selected inorganic and organometallic labeled compounds as potential radiopharmaceuticals. It is felt by the authors that further biological studies with 45Ti are justified. (U.K.)