Late Clinical and Laboratory Manifestations of Thorotrast Administration in Cerebral Arteriography

Thirty patients who received thorotrast for cerebral arteriography from 1948 to 1952 were studied to determine the delayed effects of chronic low-dose internal-emitter radiation. The whole-body burdens ranged from 0.13 to 2.5 gram-equivalents of radioactive thorium and varied with the total amount of thorotrast originally administered. Bromsulfalein retention ranged from 5 to 27 per cent, and alkaline phosphatase from 4.7 to 9.8 units in over half the patients. Most had a moderate relative increase in the albumin and a decrease in the globulin fraction on serum protein electrophoresis. Only three patients had completely normal results on liver-function tests. Chromosome analyses of white blood cells revealed chromosomal breaks and abnormalities in nine of 10 patients. There were no radiation-related abnormal physical findings, no increase in tumor incidence and no consistent changes in red-cell morphology.