POST-RADIOIODINE GRAVES' MANAGEMENT: THE PRAGMA STUDY.
Perros P., Basu A., Boelaert K., Dayan C., Vaidya B., Williams GR., Lazarus JH., Hickey J., Drake WM., Crown A., Orme SM., Johnson A., Ray DW., Leese GP., Hugh Jones T., Abraham P., Grossman A., Rees A., Razvi S., Gibb FW., Moran C., Madathil A., Žarković MP., Plummer Z., Jarvis S., Falinska A., Velusamy A., Sanderson V., Pariani N., Atkin SL., Syed AA., Sathyapalan T., Nag S., Gilbert J., Gleeson H., Levy MJ., Johnston C., Sturrock N., Bennett S., Mishra B., Malik I., Karavitaki N.
OBJECTIVE: Thyroid status in the months following radioiodine treatment for Graves' disease can be unstable.Our objective was to quantify frequency of abnormal thyroid function post-radioiodine and compare effectiveness of common management strategies. DESIGN: Retrospective, multi-centre, observational study. PATIENTS: Adult patients with Graves' disease treated with radioiodine with 12 months' follow-up. MEASUREMENTS: Euthyroidism was defined as both serum thyrotropin (TSH) and free thyroxine (FT4) within their reference ranges or, when only one was available, it was within its reference range; hypothyroidism as TSH ≥ 10 mu/L, or subnormal FT4 regardless of TSH; hyperthyroidism as TSH below and FT4 above their reference ranges; dysthyroidism as the sum of hypo- and hyperthyroidism; subclinical hypothyroidism as normal FT4 and TSH between the upper limit of normal and <10 mu/L; subclinical hyperthyroidism as low TSH and normal FT4 RESULTS: Of 812 patients studied post-radioiodine, hypothyroidism occurred in 80.7% and hyperthyroidism in 48.6% of patients. Three principal post-radioiodine management strategies were employed: (a) anti-thyroid drugs alone, (b) levothyroxine alone and (c) combination of the two. Differences among these were small. Adherence to national guidelines regarding monitoring thyroid function in the first 6 months was low (21.4-28.7%). No negative outcomes (new-onset/exacerbation of Graves' orbitopathy, weight gain, cardiovascular events), were associated with dysthyroidism. There were significant differences in demographics, clinical practice, and thyroid status post-radioiodine between centres. CONCLUSIONS: Dysthyroidism in the 12 months post-radioiodine was common. Differences between post-radioiodine strategies were small, suggesting these interventions alone are unlikely to address the high frequency of dysthyroidism. CLINICAL TRIAL REGISTRATION: Clinical. TRIALS: gov (identifier No. NCT01885533). This article is protected by copyright. All rights reserved.