Objective: To assess the efficacy of the administered doses of Radioiodine (RAI) in the treatment of patients with hyperthyroidism in Graves' disease, calculated on the basis of gland size and morphology (assessment by palpation and scintigraphy), analyzing which variables influence the final result of our sample, and on the early development of hypothyroidism.
Methods: 99 patients treated with RAI between april 1996 and november 2000 were evaluated retrospectively, 77 women and 22 men, mean age 44 years (range: 18-76). 67 patients received treatment with oral antithyroid drugs. The administered dose range was: 185-629 MBq. Mean follow-up time was 13.4 months. Success was defined as elimination of hyperthyroidism; and early hypothyroidism which appeared in the six months after therapy.
Results: 30 patients remained with euthyroidism, 53 patients had hypothyroidism and 16 had recurrent hyperthyroidism. A total of 84% of the patients were controlled with one dose of RAI. Only the time of evolution influenced the final results. The rest of the variables (gender, age, doses and antithyroid drugs) did not influence them. No relationship was found between the appearance of early/late hypothyroidism and the administered doses. A certain tendency was found for early hypothyroidism to appear in the youngest patients (p = 0.111).
Conclusions: The administered doses in our department have been shown to be effective in controlling thyrotoxicosis. In our sample, only time of evolution influenced on the final results of the patients. Only the age factor showed a certain tendency in the evolution to early/late hypothyroidism.