Analysis of 2 125 patients with hyperthyroidism after 131I therapy: a retrospective study

Objective To analyze the efficacy of 131I therapy for Graves' disease, and to investigate the incidences of complete remission and hypothyroidism after single or multiple treatments. Methods Altogether 2 125 patients with Graves' disease(614 males, 1 511 females)aged(39.8±10.2)years received 131I treatment. The diagnostic and therapeutic procedures were carried out as follows: physical examination, determination of thyroid hormones and antibodies, undergoing 131I uptake test to obtain maximum of thyroid uptake value and effective half-life time, ultrasonography, thyroid imaging, calculating 131I therapeutic dosage, 131I treatment, follow-up appraisal of curative effect. The data were analyzed by χ2 test, optimal scale regression, logistic regression and discriminant analysis. Results The rates of complete remission, hypothyroidism, partial response, and invalid in the 2 125 cases more than half a year after 131I therapy were 54.3%, 21.3%, 20.3%, and 4.1% respectively. In all patients the rate of clinical cure(including complete remission and hypothyroidism)and rate of effectiveness were 75.6% and 95.9% respectively. The rate of recovery and incidence of hypothyroidism in patients who accepted single 131I treatment were 52.4% and 21.2% respectively, while in patients who accepted twice or multiple 131I therapy the respective figures became 66.2% and 21.8% accordingly. The influential factors in the effectiveness of 131I treatment included age, thyroid weight, TSH receptor antibody(TRAb), and dose of 131I per gram of thyroid. Conclusions Patients who did not achieve clinical cure for over 6 months after first 131I treatment, may receive another131I therapy to further improve the remission rate. Age, thyroid weight, TRAb etc, contribute to the efficacy of 131I therapy for Graves' disease. The multi-perspective and multi-factor analysis would have the benefit to establish individualized treatment strategy. (Chin J Endocrinol Metab, 2015, 31: 421-426) Key words: Hyperthyroidism; 131I therapy; Dose; Follow-up studies