Brain Scanning With Chlormerodrin Hg197 and Chlormerodrin Hg203

Abstract

Early experience in brain tumor localization at this institution, utilizing diiodofluorescein I¹³¹ and scintillation counter "spot checking," proved this technique suitable only for screening.^1,2 Further progress elsewhere included development of scanning scintillation detectors,³ photographic recording,^4,5 and more suitable scanning agents including radiomercury-labeled chlormerodrin (Neohydrin).⁶ Our 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 Hg²⁰³ tagged to chlormerodrin. This compound was introduced in 1959 as an agent for brain scanning by Blau and Bender⁶ who found it significantly better than albumin I^131.7 Hg²⁰³ decays 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.