GEORGE CRILE, M.D.
Department of General Surgery,
E. PERRY McCULLAGH, M.D.
Department of Endocrinology
OTTO GLASSER, Ph.D
THE use of radioactive iodine in the treatment of hyperthyroidism was initiated seven years ago by Hertz and Roberts1 in Boston and Hamilton and Soley2 in San Francisco. The iodine was made in cyclotrons and was not available for general use. Two years ago, however, the Atomic Energy Commission released I131, prepared in the atomic pile at Oak Ridge, to any institution with a committee composed of a qualified radiologist, surgeon, and internist. Since then radioactive iodine has been used extensively throughout the country in the treatment of hyperthyroidism. This paper is a report of the results obtained at the Cleveland Clinic in the treatment of 105 patients with hyperthyroidism.
The Nature of I131
I131 differs from many radioactive substances in that its half life, or the length of time it takes to expend one half of its potential radioactivity, is only eight days. At the end of a month most of the radioactivity is gone, and by two or three months practically none remains. Since the radioactivity of I131 disappears in a short time there is no danger of later ill effects due to retention of a long-lived radioactive substance in the body.
A second characteristic of I131 which increases the safety of its use in the treatment of hyperthyroidism is the fact that its radiation is largely in the form of beta rays. These rays do not penetrate the tissues for more than 1 or 2 mm., about the thickness of a thumbnail. Since the radioactive material. . .