In 1946, fission-derived radioiodine became readily available as a by-product of the Manhattan project in Oak Ridge, TN. Hundreds of patients were treated within a few years, both for hyperthyroidism and for thyroid cancer. A new treatment, based on the physiological application of a radioisotope of iodine, was then a reality.

in 1942. Oak Ridge, Tennessee was home to several massive Manhattan Project facilities employing thousands of workers during and after World War II and was the headquarters for the project after relocating from New York City.