Brain Scanning With Chlormerodrin Hg197 and Chlormerodrin Hg203

Early experience in brain tumor localization at this institution, utilizing diiodofluorescein I¹³¹and scintillation counter "spot checking," proved this technique suitable only for screening.¹,²Further progress elsewhere included development of scanning scintillation detectors,³photographic recording,⁴,⁵and more suitable scanning agents including radiomercury-labeled chlormerodrin (Neohydrin).⁶Our present program utilizing the above refinements in equipment and radiomercury-tagged chlormerodrin has proved useful in the localization of intracranial tumors in the majority of cases prior to contrast studies. The isotope initially used was Hg²⁰³tagged to chlormerodrin. This compound was introduced in 1959 as an agent for brain scanning by Blau and Bender⁶who found it significantly better than albumin I131.7Hg²⁰³decays with a half life of 45.8 days with the emission of a low energy β-particle to an excited state of Tl²⁰³, which in turn emits a single 0.28 mev γ-ray.