Treatment of Hyperthyroidism with Individually Calculated Doses of I131

Abstract

Radioactive iodine has been used for the treatment of hyperthyroidism for 14 years. During this time no entirely satisfactory method of dosimetry has been developed. Some institutions employ "shotgun" doses, ranging from 3 to 9 mc., depending on the severity of the disease or size of the thyroid gland,^1-4 while others attempt to administer 100 to 250μc for each gram of estimated thyroid weight.^5-8 A number of groups have taken other factors into account, namely, the number of roentgen equivalents to be administered to the hyperthyroid gland, the maximum per cent uptake of a tracer dose of I¹³¹, and the "effective" or observable half-life, as well as the thyroid gland size and weight.^9-11 Allen and Goodwin,¹² in 1952, reported a method of calculating the weight of the thyroid gland based on point by point plot of the thyroid area following a tracer dose of I