Cerebral Uptake of Radioiodinated Amphetamines — Basic Research and Clinical Results

In 1975, Sargent et al (1) were the first to point out the potentialities of scintigraphic brain imaging with radioactive amphetamines using Br77 labelled dimethoxy phenyl isopropyl amphetamine as a tracer. Five years later Winchell et al (2,3) published their pioneer work on cerebral uptake and organ kinetics of amphetamine derivatives which led to the clinical use of N-isopropyl amphetamine (IMP). At present IMP and HIPDM SPECT has become a routine tool for nuclear brain imaging (4–12).Since 1983 we had the opportunity to perform brain 123 SPECT with I123 -IMP provided by Amersham Buchler for research purposes (4). However, due to the fact that there is only 5 to 10% cerebral uptake (13) relatively high amounts of the I123 labelled tracer have to be administered resulting in high costs. Above that, its extensive pulmonary retention leads to a high radiation burden to this organ. These reasons prompted us to evaluate other tracers with superior properties for brain imaging.