Localization of Focal Intracranial Lesions by Scanning of Rays From Position-Emitting Isotopes

Positron-emitting isotopes of arsenic and copper, injected intravenously, were used for the localization of braiiwn tumors and other intracranial lesions. Scanning was accomplished by coincidence counting of the paired annihilation gamma rays from the positron-emitting copper or arsenic. The biological reactions of inorganic arsenate and arsenite and of copper vetsenate in man are discussed. Radioassay of biopsies of the principal normal cephalic tissues, of various types of neoplasms, of hematomas, abscesses, and zones of demyelination was carried out. Concentrations of isotopes were increased in all tumors. Hematomas, abscesses, and large zones of demyelination also had concentrations high enough to permit localization in the majority of patients. The results of more than 3000 scans on 334 patients are summarized. A correct diagnosis was made in 80% of 249 tumors scanned with arsenic and in 70% of 84 tumors scanned with copper. 19 references. (C.H.)