111In-labelled baboon platelets: The influence of in vivo redistribution and contaminating 114mIn on the radiation dose

In five normal baboons, whole body 111In decreased slowly (tsol 12 = 60 days) after the end of platelet lifespan. There was slight elution of radioactivity from the liver and spleen, the important sites of platelet sequestration. A fraction of this eluted radioactivity accumulated in the bone marrow, but also in other tissues. This redistribution did not have a significant effect on the measurement of in vivo platelet kinetics. It did however, diminish the total weighted radiation dose, especially that due to contaminating 114mIn.