Treatment of solitary toxic thyroid nodule with 131I: results in 43 patients
Marín, J.F.; Maraña, G.; Salto, L.; Astigarraga, B.; Estrada, F.J.; Lucas, T.; Barceló, B.
Medicina Clinica 96(19): 730-732
1991
ISSN/ISBN: 0025-7753 PMID: 1875750 Document Number: 385181
Evaluation of the therapy with high-dose 131I in solitary toxic thyroid adenoma, with particular attention to the effects on thyroid function and on the nodular size. A retrospective study of 43 patients with solitary thyroid nodule treated with radioactive iodine (mean dose 26.6 mCi, range 10-35) and followed up for 49.7 +/- 36.6 months (range 6-186) with periodical clinical, laboratory and echographic evaluations. Thirty-two patients (74.4%) had a normal thyroid function during follow-up. Five (11.6%) remained with hyperthyroidism and in 6 (13.9%) hypothyroidism developed 6-30 months after the administration of radioactive iodine. Three of these 6 had subclinical hypothyroidism, with mild increases in serum thyrotropin (TSH). Neither the development of hypothyroidism nor its persistence were significantly correlated with the initial thyroxin (T4) or triiodothyronine (T3) levels, the nodular size, the 131I dose, the incomplete inhibition of the extranodular thyroid parenchyma or the previous therapy with antithyroid drugs. The nodule diminished in size in 15 cases (38.4%), it disappeared in 9 (23%), it remained unchanged in 12 (30.7%) and it increased in 3 (7.7%). The treatment of the solitary toxic thyroid nodule with relatively high 131I doses is a safe and effective procedure, with a prevalence of residual hypothyroidism which is lower than previously reported. The disappearance of the nodule was only achieved in a minority of cases.