title: Incidence of hypothyroidism occurring long after iodine-131 therapy for hyperthyroidism.
abstract: We have studied the long-term incidence of hypothyroidism in 4,473 formerly hyperthyroid patients given I-131 therapy between 1951 and 1975. The mean age at the first I-131 treatment was 56 yr. Six percent developed hypothyroidism within one year of therapy, and 72% within 26 yr. Prior antithyroid medication did not affect the incidence of hypothyroidism. Patients cured with one dose of I-131 had a lower cumulative long-term incidence of hypothyroidism than those requiring more than one dose.
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D004812:Epidemiologic Methods; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006980:Hyperthyroidism / Q000532:radiotherapy* / Q000601:surgery; D007037:Hypothyroidism / Q000209:etiology*; D007457:Iodine Radioisotopes / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D011336:Probability; D013548:Sweden; D013961:Thyroid Gland / Q000473:pathology / Q000528:radiation effects; D013997:Time Factors
chemical_list: D007457:Iodine Radioisotopes