ABSTRACT
In this study, the dose rates at various distances of 5, 10, 50 and 100 cm from 70 patients, who were administered diagnostic amounts of 201Tl-chloride and 99Tcm-MIBI, was measured using an ionisation chamber. The maximum values of external dose rates of 201Tl and 99Tcm-MIBI were 11.2 microSv.h-1 +/- 2.3 and 43.1 microSv.h-1 +/- 11.9 respectively at 5 cm from the patients. Significant exposure from patients after injection of 99Tcm-MIBI was limited on the day of administration. Departure dose rates of 201Tl fell gradually so by 3 days after administration were significant. All excreted urine was also collected from 16 patients for the 24 days after administration. The urinary excretion rate of 201Tl was slow; about 2% of the activity within 24 h after injection. The urinary excretion of 99Tcm-MIBI was rapid, and a large amount of activity was excreted in a few hours after injection; 22% within 20 h after injection.
