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Radioiodine in the treatment of hyperthyroidism

Douglas S Ross, MD
Section Editor
David S Cooper, MD
Deputy Editor
Jean E Mulder, MD


Radioiodine is widely used for the treatment of Graves' hyperthyroidism. It has been the therapy of choice in the United States, selected by 60 percent of thyroid specialists who responded to a survey in 2011 but only 13 percent of European thyroid specialists [1]. Low rates of use were also reported in surveys in the United Kingdom and Australia [2,3].

Radioiodine is administered orally as sodium iodide (131-I) in solution or a capsule. The radioiodine is rapidly incorporated into the thyroid, and its beta emissions result in extensive local tissue damage. The net effect is ablation of thyroid function over a period of 6 to 18 weeks.

Radioiodine for the treatment of hyperthyroidism will be reviewed here. Other treatment options for Graves' hyperthyroidism and toxic adenoma and toxic multinodular goiter (MNG) are reviewed separately. (See "Graves' hyperthyroidism in nonpregnant adults: Overview of treatment" and "Treatment of toxic adenoma and toxic multinodular goiter".)


Graves' disease — The therapeutic approach to Graves' hyperthyroidism consists of both rapid amelioration of symptoms with a beta blocker and measures aimed at decreasing thyroid hormone synthesis with either the administration of a thionamide, radioiodine ablation, or surgery [4]. Because all three treatment modalities are effective, the choice of therapy should involve active discussion between clinician and patient (table 1).

Radioiodine has been the most popular treatment for hyperthyroidism in the United States, although use of thionamides may be increasing [5]. Radioiodine is less popular outside of the United States [1-3,6]. The choice of therapy for Graves' disease is reviewed separately. (See "Graves' hyperthyroidism in nonpregnant adults: Overview of treatment", section on 'Choice of therapy'.)


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Literature review current through: Sep 2016. | This topic last updated: Oct 14, 2016.
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  1. Burch HB, Burman KD, Cooper DS. A 2011 survey of clinical practice patterns in the management of Graves' disease. J Clin Endocrinol Metab 2012; 97:4549.
  2. Vaidya B, Williams GR, Abraham P, Pearce SH. Radioiodine treatment for benign thyroid disorders: results of a nationwide survey of UK endocrinologists. Clin Endocrinol (Oxf) 2008; 68:814.
  3. Walsh JP. Management of Graves' disease in Australia. Aust N Z J Med 2000; 30:559.
  4. Abraham P, Acharya S. Current and emerging treatment options for Graves' hyperthyroidism. Ther Clin Risk Manag 2010; 6:29.
  5. Brito JP, Schilz S, Singh Ospina N, et al. Antithyroid Drugs-The Most Common Treatment for Graves' Disease in the United States: A Nationwide Population-Based Study. Thyroid 2016; 26:1144.
  6. Ross DS. Radioiodine therapy for hyperthyroidism. N Engl J Med 2011; 364:542.
  7. Ross DS, Burch HB, Cooper DS, et al. 2016 American Thyroid Association Guidelines for Diagnosis and Management of Hyperthyroidism and Other Causes of Thyrotoxicosis. Thyroid 2016; 26:1343.
  8. Evans PM, Webster J, Evans WD, et al. Radioiodine treatment in unsuspected pregnancy. Clin Endocrinol (Oxf) 1998; 48:281.
  9. Berg GE, Nyström EH, Jacobsson L, et al. Radioiodine treatment of hyperthyroidism in a pregnant women. J Nucl Med 1998; 39:357.
  10. Stoffer SS, Hamburger JI. Inadvertent 131I therapy for hyperthyroidism in the first trimester of pregnancy. J Nucl Med 1976; 17:146.
  11. Welch CR, Hocking M, Franklyn JA, Whittle MJ. Fetal thyrotrophin: the best indicator of long term thyroid function after in utero exposure to iodine-131? Fetal Diagn Ther 1998; 13:176.
  12. Thorpe-Beeston JG, Nicolaides KH, McGregor AM. Fetal thyroid function. Thyroid 1992; 2:207.
  13. Mariotti S, Martino E, Francesconi M, et al. Serum thyroid autoantibodies as a risk factor for development of hypothyroidism after radioactive iodine therapy for single thyroid 'hot' nodule. Acta Endocrinol (Copenh) 1986; 113:500.
  14. Eckstein AK, Plicht M, Lax H, et al. Thyrotropin receptor autoantibodies are independent risk factors for Graves' ophthalmopathy and help to predict severity and outcome of the disease. J Clin Endocrinol Metab 2006; 91:3464.
  15. Shafer RB, Nuttall FQ. Acute changes in thyroid function in patients treated with radioactive iodine. Lancet 1975; 2:635.
  16. Burch HB, Solomon BL, Cooper DS, et al. The effect of antithyroid drug pretreatment on acute changes in thyroid hormone levels after (131)I ablation for Graves' disease. J Clin Endocrinol Metab 2001; 86:3016.
  17. Stensvold AD, Jorde R, Sundsfjord J. Late and transient increases in free T4 after radioiodine treatment for Graves' disease. J Endocrinol Invest 1997; 20:580.
  18. Okamura K, Ikenoue H, Shiroozu A, et al. Reevaluation of the effects of methylmercaptoimidazole and propylthiouracil in patients with Graves' hyperthyroidism. J Clin Endocrinol Metab 1987; 65:719.
  19. Ross DS, Daniels GH, De Stefano P, et al. Use of adjunctive potassium iodide after radioactive iodine (131I) treatment of Graves' hyperthyroidism. J Clin Endocrinol Metab 1983; 57:250.
  20. Alexander EK, Larsen PR. High dose of (131)I therapy for the treatment of hyperthyroidism caused by Graves' disease. J Clin Endocrinol Metab 2002; 87:1073.
  21. Nakamura H, Noh JY, Itoh K, et al. Comparison of methimazole and propylthiouracil in patients with hyperthyroidism caused by Graves' disease. J Clin Endocrinol Metab 2007; 92:2157.
  22. Walter MA, Briel M, Christ-Crain M, et al. Effects of antithyroid drugs on radioiodine treatment: systematic review and meta-analysis of randomised controlled trials. BMJ 2007; 334:514.
  23. Imseis RE, Vanmiddlesworth L, Massie JD, et al. Pretreatment with propylthiouracil but not methimazole reduces the therapeutic efficacy of iodine-131 in hyperthyroidism. J Clin Endocrinol Metab 1998; 83:685.
  24. Santos RB, Romaldini JH, Ward LS. Propylthiouracil reduces the effectiveness of radioiodine treatment in hyperthyroid patients with Graves' disease. Thyroid 2004; 14:525.
  25. Bonnema SJ, Bennedbaek FN, Veje A, et al. Continuous methimazole therapy and its effect on the cure rate of hyperthyroidism using radioactive iodine: an evaluation by a randomized trial. J Clin Endocrinol Metab 2006; 91:2946.
  26. Dunkelmann S, Kuenstner H, Nabavi E, et al. Change in the intrathyroidal kinetics of radioiodine under continued and discontinued antithyroid medication in Graves' disease. Eur J Nucl Med Mol Imaging 2007; 34:228.
  27. Kubota S, Ohye H, Yano G, et al. Two-day thionamide withdrawal prior to radioiodine uptake sufficiently increases uptake and does not exacerbate hyperthyroidism compared to 7-day withdrawal in Graves' disease. Endocr J 2006; 53:603.
  28. Walter MA, Christ-Crain M, Schindler C, et al. Outcome of radioiodine therapy without, on or 3 days off carbimazole: a prospective interventional three-group comparison. Eur J Nucl Med Mol Imaging 2006; 33:730.
  29. Bonnema SJ, Bennedbaek FN, Gram J, et al. Resumption of methimazole after 131I therapy of hyperthyroid diseases: effect on thyroid function and volume evaluated by a randomized clinical trial. Eur J Endocrinol 2003; 149:485.
  30. Shiber S, Stiebel-Kalish H, Shimon I, et al. Glucocorticoid regimens for prevention of Graves' ophthalmopathy progression following radioiodine treatment: systematic review and meta-analysis. Thyroid 2014; 24:1515.
  31. Bartalena L, Marcocci C, Bogazzi F, et al. Use of corticosteroids to prevent progression of Graves' ophthalmopathy after radioiodine therapy for hyperthyroidism. N Engl J Med 1989; 321:1349.
  32. Bartalena L, Marcocci C, Bogazzi F, et al. Relation between therapy for hyperthyroidism and the course of Graves' ophthalmopathy. N Engl J Med 1998; 338:73.
  33. Lai A, Sassi L, Compri E, et al. Lower dose prednisone prevents radioiodine-associated exacerbation of initially mild or absent graves' orbitopathy: a retrospective cohort study. J Clin Endocrinol Metab 2010; 95:1333.
  34. Vannucchi G, Campi I, Covelli D, et al. Graves' orbitopathy activation after radioactive iodine therapy with and without steroid prophylaxis. J Clin Endocrinol Metab 2009; 94:3381.
  35. Träisk F, Tallstedt L, Abraham-Nordling M, et al. Thyroid-associated ophthalmopathy after treatment for Graves' hyperthyroidism with antithyroid drugs or iodine-131. J Clin Endocrinol Metab 2009; 94:3700.
  36. Hautzel H, Pisar E, Yazdan-Doust N, et al. Qualitative and quantitative impact of protective glucocorticoid therapy on the effective 131I half-life in radioiodine therapy for Graves disease. J Nucl Med 2010; 51:1917.
  37. Bogazzi F, Giovannetti C, Fessehatsion R, et al. Impact of lithium on efficacy of radioactive iodine therapy for Graves' disease: a cohort study on cure rate, time to cure, and frequency of increased serum thyroxine after antithyroid drug withdrawal. J Clin Endocrinol Metab 2010; 95:201.
  38. Bal CS, Kumar A, Pandey RM. A randomized controlled trial to evaluate the adjuvant effect of lithium on radioiodine treatment of hyperthyroidism. Thyroid 2002; 12:399.
  39. Bogazzi F, Bartalena L, Campomori A, et al. Treatment with lithium prevents serum thyroid hormone increase after thionamide withdrawal and radioiodine therapy in patients with Graves' disease. J Clin Endocrinol Metab 2002; 87:4490.
  40. Franklyn JA. The management of hyperthyroidism. N Engl J Med 1994; 330:1731.
  41. Ross DS, Ridgway EC, Daniels GH. Successful treatment of solitary toxic thyroid nodules with relatively low-dose iodine-131, with low prevalence of hypothyroidism. Ann Intern Med 1984; 101:488.
  42. Goldstein R, Hart IR. Follow-up of solitary autonomous thyroid nodules treated with 131I. N Engl J Med 1983; 309:1473.
  43. Nygaard B, Faber J, Veje A, et al. Transition of nodular toxic goiter to autoimmune hyperthyroidism triggered by 131I therapy. Thyroid 1999; 9:477.
  44. Allahabadia A, Daykin J, Sheppard MC, et al. Radioiodine treatment of hyperthyroidism-prognostic factors for outcome. J Clin Endocrinol Metab 2001; 86:3611.
  45. Rapoport B, Caplan R, DeGroot LJ. Low-dose sodium iodide I 131 therapy in Graves disease. JAMA 1973; 224:1610.
  46. Goolden AW, Stewart JS. Long-term results from graded low dose radioactive iodine therapy for thyrotoxicosis. Clin Endocrinol (Oxf) 1986; 24:217.
  47. Sridama V, McCormick M, Kaplan EL, et al. Long-term follow-up study of compensated low-dose 131I therapy for Graves' disease. N Engl J Med 1984; 311:426.
  48. Farrar JJ, Toft AD. Iodine-131 treatment of hyperthyroidism: current issues. Clin Endocrinol (Oxf) 1991; 35:207.
  49. Peters H, Fischer C, Bogner U, et al. Radioiodine therapy of Graves' hyperthyroidism: standard vs. calculated 131iodine activity. Results from a prospective, randomized, multicentre study. Eur J Clin Invest 1995; 25:186.
  50. Jarløv AE, Hegedüs L, Kristensen LO, et al. Is calculation of the dose in radioiodine therapy of hyperthyroidism worth while? Clin Endocrinol (Oxf) 1995; 43:325.
  51. Leslie WD, Ward L, Salamon EA, et al. A randomized comparison of radioiodine doses in Graves' hyperthyroidism. J Clin Endocrinol Metab 2003; 88:978.
  52. Holst JP, Burman KD, Atkins F, et al. Radioiodine therapy for thyroid cancer and hyperthyroidism in patients with end-stage renal disease on hemodialysis. Thyroid 2005; 15:1321.
  53. Nibhanupudy JR, Hamilton W, Sridhar R, et al. Iodine-131 treatment of hyperthyroidism in a patient on dialysis for chronic renal failure. Am J Nephrol 1993; 13:214.
  54. American Thyroid Association Taskforce On Radioiodine Safety, Sisson JC, Freitas J, et al. Radiation safety in the treatment of patients with thyroid diseases by radioiodine 131I : practice recommendations of the American Thyroid Association. Thyroid 2011; 21:335.
  55. United States Nuclear Regulatory Commission (NRC). Consolidated Guidance About Materials Licenses: Program-Specific Guidance About Medical Use Licenses, 2008. http://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr1556/v9/r2/sr1556v9r2-final.pdf#08-36 (Accessed on May 06, 2011).
  56. Mathieu I, Caussin J, Smeesters P, et al. Doses in family members after 131I treatment. Lancet 1997; 350:1074.
  57. Beckers C. Regulations and policies on radioiodine 131I therapy in Europe. Thyroid 1997; 7:221.
  58. Safa AM, Schumacher OP, Rodriguez-Antunez A. Long-term follow-up results in children and adolescents treated with radioactive iodine (131I) for hyperthyroidism. N Engl J Med 1975; 292:167.
  59. Robertson JS, Gorman CA. Gonadal radiation dose and its genetic significance in radioiodine therapy of hyperthyroidism. J Nucl Med 1976; 17:826.
  60. Graham GD, Burman KD. Radioiodine treatment of Graves' disease. An assessment of its potential risks. Ann Intern Med 1986; 105:900.
  61. Stan MN, Durski JM, Brito JP, et al. Cohort study on radioactive iodine-induced hypothyroidism: implications for Graves' ophthalmopathy and optimal timing for thyroid hormone assessment. Thyroid 2013; 23:620.
  62. Davies PH, Franklyn JA, Daykin J, Sheppard MC. The significance of TSH values measured in a sensitive assay in the follow-up of hyperthyroid patients treated with radioiodine. J Clin Endocrinol Metab 1992; 74:1189.
  63. Uy HL, Reasner CA, Samuels MH. Pattern of recovery of the hypothalamic-pituitary-thyroid axis following radioactive iodine therapy in patients with Graves' disease. Am J Med 1995; 99:173.
  64. Aizawa Y, Yoshida K, Kaise N, et al. The development of transient hypothyroidism after iodine-131 treatment in hyperthyroid patients with Graves' disease: prevalence, mechanism and prognosis. Clin Endocrinol (Oxf) 1997; 46:1.
  65. Holm LE, Lundell G, Israelsson A, Dahlqvist I. Incidence of hypothyroidism occurring long after iodine-131 therapy for hyperthyroidism. J Nucl Med 1982; 23:103.
  66. Markovic V, Eterovic D. Thyroid echogenicity predicts outcome of radioiodine therapy in patients with Graves' disease. J Clin Endocrinol Metab 2007; 92:3547.
  67. Hoogenberg K, Beentjes JA, Piers DA. Lithium as an adjunct to radioactive iodine in treatment-resistant Graves thyrotoxicosis. Ann Intern Med 1998; 129:670.
  68. Ma C, Xie J, Wang H, et al. Radioiodine therapy versus antithyroid medications for Graves' disease. Cochrane Database Syst Rev 2016; 2:CD010094.
  69. Chiovato L, Fiore E, Vitti P, et al. Outcome of thyroid function in Graves' patients treated with radioiodine: role of thyroid-stimulating and thyrotropin-blocking antibodies and of radioiodine-induced thyroid damage. J Clin Endocrinol Metab 1998; 83:40.
  70. Tallstedt L, Lundell G, Tørring O, et al. Occurrence of ophthalmopathy after treatment for Graves' hyperthyroidism. The Thyroid Study Group. N Engl J Med 1992; 326:1733.
  71. Kung AW, Yau CC, Cheng A. The incidence of ophthalmopathy after radioiodine therapy for Graves' disease: prognostic factors and the role of methimazole. J Clin Endocrinol Metab 1994; 79:542.
  72. Sridama V, DeGroot LJ. Treatment of Graves' disease and the course of ophthalmopathy. Am J Med 1989; 87:70.
  73. Gwinup G, Elias AN, Ascher MS. Effect on exophthalmos of various methods of treatment of Graves' disease. JAMA 1982; 247:2135.
  74. Perros P, Kendall-Taylor P, Neoh C, et al. A prospective study of the effects of radioiodine therapy for hyperthyroidism in patients with minimally active graves' ophthalmopathy. J Clin Endocrinol Metab 2005; 90:5321.
  75. Laurberg P, Wallin G, Tallstedt L, et al. TSH-receptor autoimmunity in Graves' disease after therapy with anti-thyroid drugs, surgery, or radioiodine: a 5-year prospective randomized study. Eur J Endocrinol 2008; 158:69.
  76. Wartofsky L. Therapeutic controversies. Summation, commentary, and overview: concerns over aggravation of Graves' ophthalmopathy by radioactive iodine treatment and the use of retrobulbar radiation therapy. J Clin Endocrinol Metab 1995; 80:347.
  77. Saenger EL, Thoma GE, Tompkins EA. Incidence of leukemia following treatment of hyperthyroidism. Preliminary report of the Cooperative Thyrotoxicosis Therapy Follow-Up Study. JAMA 1968; 205:855.
  78. Ron E, Doody MM, Becker DV, et al. Cancer mortality following treatment for adult hyperthyroidism. Cooperative Thyrotoxicosis Therapy Follow-up Study Group. JAMA 1998; 280:347.
  79. Dobyns BM, Sheline GE, Workman JB, et al. Malignant and benign neoplasms of the thyroid in patients treated for hyperthyroidism: a report of the cooperative thyrotoxicosis therapy follow-up study. J Clin Endocrinol Metab 1974; 38:976.
  80. Franklyn JA, Maisonneuve P, Sheppard M, et al. Cancer incidence and mortality after radioiodine treatment for hyperthyroidism: a population-based cohort study. Lancet 1999; 353:2111.
  81. Metso S, Auvinen A, Huhtala H, et al. Increased cancer incidence after radioiodine treatment for hyperthyroidism. Cancer 2007; 109:1972.
  82. Franklyn JA, Maisonneuve P, Sheppard MC, et al. Mortality after the treatment of hyperthyroidism with radioactive iodine. N Engl J Med 1998; 338:712.
  83. Metso S, Jaatinen P, Huhtala H, et al. Increased cardiovascular and cancer mortality after radioiodine treatment for hyperthyroidism. J Clin Endocrinol Metab 2007; 92:2190.
  84. Franklyn JA, Sheppard MC, Maisonneuve P. Thyroid function and mortality in patients treated for hyperthyroidism. JAMA 2005; 294:71.
  85. Boelaert K, Maisonneuve P, Torlinska B, Franklyn JA. Comparison of mortality in hyperthyroidism during periods of treatment with thionamides and after radioiodine. J Clin Endocrinol Metab 2013; 98:1869.
  86. Flynn RW, Macdonald TM, Jung RT, et al. Mortality and vascular outcomes in patients treated for thyroid dysfunction. J Clin Endocrinol Metab 2006; 91:2159.
  87. Metso S, Auvinen A, Salmi J, et al. Increased long-term cardiovascular morbidity among patients treated with radioactive iodine for hyperthyroidism. Clin Endocrinol (Oxf) 2008; 68:450.
  88. Read CH Jr, Tansey MJ, Menda Y. A 36-year retrospective analysis of the efficacy and safety of radioactive iodine in treating young Graves' patients. J Clin Endocrinol Metab 2004; 89:4229.
  89. Ceccarelli C, Canale D, Battisti P, et al. Testicular function after 131I therapy for hyperthyroidism. Clin Endocrinol (Oxf) 2006; 65:446.
  90. Harvey RD, Metcalfe RA, Morteo C, et al. Acute pre-tibial myxoedema following radioiodine therapy for thyrotoxic Graves' disease. Clin Endocrinol (Oxf) 1995; 42:657.