Successful treatment of solitary toxic thyroid nodules with relatively low-dose iodine-131, with low prevalence of hypothyroidism.
Forty-five patients with solitary toxic thyroid adenomas received 131I (mean dose, 10.3 mCi) for treatment of hyperthyroidism and were followed for 4.9 +/- 3.2 years (range, 0.5 to 13.5). Seventy-seven percent were euthyroid by 2 months, 91% by 6 months, and 93% by 1 year. Only 3 patients did not respond to a single dose of 131I, but all responded to multiple doses. Late recurrent hyperthyroidism occurred in 3 patients at 4.5, 6, and 10 years after treatment with a single dose of 131I. No patient developed clinical hypothyroidism, and none had a low serum thyroxine level associated with an elevated serum thyrotrophin level. Three patients developed minimal elevations in serum thyrotrophin levels: 1, 4, and 7.5 years after 131I treatment, their thyrotrophin levels were 8.4, 6.2, and 9.6 microU/mL, respectively. All 3 had normal serum thyroxine levels and were clinically euthyroid. Mean serum thyroxine concentrations of all patients were unchanged between 1 and more than 9 years of follow-up. These data suggest that solitary toxic adenomas may be treated with relatively low doses of 131I (5 to 15 mCi), and that post-treatment hypothyroidism is very unusual.
D000236:Adenoma / Q000150:complications / Q000532:radiotherapy*; D000328:Adult; D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006980:Hyperthyroidism / Q000209:etiology / Q000532:radiotherapy*; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D013964:Thyroid Neoplasms / Q000150:complications / Q000532:radiotherapy*; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood
D007457:Iodine Radioisotopes; D013972:Thyrotropin; D013974:Thyroxine