Radiation Dosimetry in the Treatment of Functional Thyroid Carcinoma with I131

Abstract

Methods are described for estimating dosage in I131 therapy. These methods require adaptation to particular cases, but certain common features have been considered. The method of calculating tumor dose was shown for one individual. A rough estimate of the max. possible radiation doses delivered to blood, kidney, mouth, and stomach in patients undergoing I131 therapy was attempted on the basis of the radioactivity found in blood, urine, saliva, and gastric juice. It is found that, on the avg., admn. of 100 mc of I131, produces a total-body radiation dose of 108 er. Individual variations may shift this value by a factor as great as 3 in either direction. For the same amount of I131, the avg. max. "kidney" dose is 757 er; the avg. max. "gastric" dose if 771 er, and the avg. max. "mouth" dose is 2020 er. The last 3 doses, however, must be considered as applying to very limited regions of the organs listed above.