The excretion of thorium and thorium daughters after thorotrast administration

This is the authors' abstract. We don't add key points for this paper.

a d m a n , W . B. L o o n e y and &I. C o l o d z i nThorotrast, a suspension of thorium dioxide, was widely used during the period 1930-1 945 in diagnostic radiology primarily for visualization of the liver, spleen and cerebral arteries.Thereafter its use was curtaiied, in part because 01 a low but significant incidence of injection site sequelne, and in part (9, 16) because of the recognition that thorium being the radioactive parent of a chain of radioactive daughters, might produce clinical changes or tumors.In support of the latter contention, it could be argued that the 15 gr thorium (plus its daughter products in equilibrium), contained in the 75 ml dose of Thorotrast used for hepatograms, was equivalent on an alpha particle energy basis to 2.1 pg radium.If account was taken of the respiratory loss of approximately 70 7; of the radon formed from radium, and if it were assumed that none of the 54.5 second half-life thoron was lost from the body, the thorium dose became equivalent to 4.9 pg radium.Furthermore, roentgenograms taken many pears after Thorotrast administration did not show any significant decrease in density over the liver and spleen.Since the total weight of the reticular endothelial system is very nearly equal to that of the skeleton (the site of deposition of radium) the average alpha energyigram tissueiunit time would be in the approximate relation of ~ _ _