Radiology, Vol 156, 183-185, Copyright © 1985 by Radiological Society of North America
Thyroid radiation absorbed dose from diagnostic procedures in U.S. population
RD Rosenberg, FA Mettler Jr, RD Moseley Jr, T Parker, AG Williams, JH Christie and CA Kelsey
According to a 1981 survey of thyroid imaging methods in the United States,
radionuclide thyroid scans and uptake studies increased 250%- 300% between
1966 and 1981, while the U.S. population increased only 17%. Collective
absorbed dose decreased from 18 X 10(6) rad (18 X 10(4) Gy) in 1966 to 13.9
X 10(6) rad (13.9 X 10(4) Gy) in 1981. The decrease was due to the use of
iodine 123 and technetium 99m pertechnetate rather than iodine 131 (I-131
was used for 100% of scans and uptake studies in 1966 and 10% and 54%,
respectively, in 1981) and also to fewer free-standing thyroid uptake
studies (150,000 in 1966 and 33,000 in 1981). Even with reduced usage,
I-131 still accounted for 93% of the collective absorbed dose in 1981. If
I-131 were eliminated from diagnostic procedures, the annual absorbed dose
would decrease to 1.4 X 10(6) rad (1.4 X 10(4) Gy). The number of
radiation-induced cancer cases would also be reduced.
