Production and use of 123I

Iodine-123 has been produced by a variety of nuclear reactions and is presently available commercially with a few percent longer lived, higher energy radioiodine contaminants. The clinical evaluation of the impure radionuclide shows it to yield comparable image quality to that obtained using 131I. The impure 123I is preferred to 131I because, if administered near calibration time, lower radiation exposure is given to patients. Use of high-purity 123I, however, not only gives optimal reduction in radiation exposure to the patient, but also yields better quality thyroid images when compared with /sup 99m/Tc and 131I. The production of large-scale quantities of high-purity 123I may soon be realized