Thyroid radiation absorbed dose from diagnostic procedures in US population

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 US population increased only 17%. Collective absorbed dose decreased from 18 x 106 rad (18 x 104 Gy) in 1966 to 13.9 x 106 rad (13.9 x 104 Gy) in 1981. The decrease was due to the use of iodine 123 and technetium 99m pertechnetate rather than iodine 131 and also to fewer free-standing thyroid uptake studies. 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 106 rad (1.4 x 104 Gy). The number of radiation-induced cancer cases would also be reduced