PROGNOSTIC VALUE OF HIGH 10-MINUTE I-131 UPTAKE IN NON-TOXIC GOITRES.

Forty-two patients with non-toxic goitre and with a high 10-minute uptake of I(131) were treated with 100 mug. of l-triiodothyronine per day for periods up to 36 months. All of the goitres were reduced in size and 10 showed marked regression within one week. Hashimoto's disease was considered an unlikely cause of these goitres because only four of 20 tested had positive antithyroglobulin tests, and these were of low titre (up to 1:81). Chromatographic studies suggested a defect in thyroxine metabolism in many of these patients. It is concluded that a high 10-minute uptake test is useful in predicting a response to therapy and in selecting patients likely to have a detectable defect in thyroxine metabolism.