October 24, 1977

Radium and Thyroid Cancer

Author Affiliations

State University of New York Downstate Medical Center Brooklyn

JAMA. 1977;238(17):1810. doi:10.1001/jama.1977.03280180014003

To the Editor.—  It might be worth emphasizing that when evaluating the thyroid of a patient with previous head-and-neck irradiation, in the context of the high incidence of thyroid cancer in these patients (237:2089, 1977), persons treated with intranasopharyngeal radium or radon should be considered separately from those treated with external beam radiation.Whereas, for example, about 95% of the patients studied by Favus et al1 received more than 700 R to the thyroid, patients that were treated with radon or radium probably received only 3 to 8 R to the thyroid. (This dose was calculated using the inverse square law,2 a distance from applicator to thyroid of 10 cm, a dose of radium of 33 to 100 mg-hours,3 and 8.25 R/hr at 1 cm as the radiation emitted by 1 mg of radium.) This relatively small dose of radiation to the thyroid is less than the