THE DOSIMETRY OF I-123 LABELED 2-BETA-CARBOMETHOXY-3-BETA-(4-IODOPHENYL)TROPANE

This report documents the radiation dosimetry of iodine-123 labelled 2 beta-carbomethoxy-3beta-(4-iodophenyl)tropane [I-123]beta-CIT in human s. The mean absorbed doses for various organs and the effective dose e quivalent were estimated from whole-body scans, blood samples and sing le-photon emission tomography scans acquired up to 22 h after the inje ction of a known amount of tracer. The basal ganglia, the liver and th e lower large intestinal wall received the highest mean absorbed doses of 0.270 mGy/MBq, 0.038 mGy/MBq and 0.034 mGy/MBq, respectively. The effective dose equivalent for adults was estimated using 11 organs and the ICRP-87 radiation dose model and was 0.031 mSv/MBq. The radiation dose to the basal ganglia limits the maximum injected activity of [I- 123]beta-CIT to 185 MBq for a single study.