Distribution and dosimetry of 111In-labeled platelets.

Abstract

The distribution of 111In-labeled platelets was studied in 5 young, healthy men. The radioactivity in the lungs, heart, liver, spleen, kidneys and testes was determined from areas-of-interest in computed .gamma.-camera scans at intervals up to 75 h after injection. After the first 4 h, the activity in each organ except the liver and kidney, decreased at roughly the physical decay rate. In the liver and kidney, the curves were relatively flat, indicating continued accumulation of the radiotracer. The calculated mean radiation absorbed dose per unit administered activity was 0.60 .+-. 0.07 rad/mCi (0.16 .+-. 0.02 Gy/GBq [gray/gigabecqueree]) for the total body and 34 .+-. 6 rad/mCi (9.0 .+-. 1.5 Gy/GBq) for the spleen.