Radioiodine treatment for graves’ disease: a 10-year Australian cohort study

Abstract

BackgroundRadioactive iodine (I131) is a common definitive treatment for Graves’ Disease. Potential complications include worsening, or new development of Graves’ eye disease and development of a radiation thyroiditis. The purpose of the present study was to assess outcomes of patients treated with I131 in an Australian tertiary centre over 10 years.MethodsData from 101 consecutive patients treated with I131 for a diagnosis of Graves’ disease between 2005 to 2015 was collected and reviewed retrospectively. Baseline TSH receptor antibody titre, pre-treatment free thyroxine (FT4), technetium scan uptake, initial treatment, duration of treatment, reason for definitive therapy, complications, and time to remission (defined as euthyroidism or hypothyroidism after 12 months) were recorded.ResultsOf the 92 patients with adequate outcome data, 73 (79.3%) patients achieved remission with a single dose of I131. Of the remaining 19 patients, 12 had a second dose and became hypothyroid. TSH receptor antibody titre at diagnosis was significantly lower in the group that achieved remission with the first dose compared with those who did not (P = 0.0071). There was no difference in technetium uptake, I131 dose, duration of therapy or pre-treatment free thyroxine (FT4). I131 was complicated by development of eye disease in 3 patients and 1 (of 11 with pre-existing eye disease) had worsening eye disease. A clinically apparent flare of hyperthyroidism following I131 was evident in 8 patients (8.6%).ConclusionRadioiodine is an effective therapy for Graves’ Disease with few complications. The majority of patients achieve remission with a single dose. Those who require a second dose are more likely to have higher TSH receptor antibody titres at diagnosis. To the best of our knowledge, this is the first study to report outcomes from radioiodine treatment for Graves’ disease in an Australian population.

Graves' Disease: Can It Be Cured?

“…In most studies remission is defined as normal serum TSH, FT4, and triiodothyronine (T3) serum concentrations lasting for 1 year without any treatment. But in a recent Australian study, remission was defined as euthyroidism or hypothyroidism after 12 months, and it was reported that 79% of patients achieved “remission” with a single dose of 131 I [ 16 ].…”

Increased Risk of Radioiodine Treatment Failure Associated with Graves Disease Refractory to Methimazole

“…TRAb becomes negative in patients who achieve disease remission on ATD therapy, and persistence of TRAb predicts ATD therapy failure (27,28). It has also been reported that high TRAb level may be associated with RAI treatment failure (29,30,31). As a result, patients who have persistent TRAb levels after ATD therapy may have higher TRAb levels prior to RAI treatment, and this may explain treatment refractoriness to both therapies.…”

Success Rate of Radioactive Iodine Therapy in Graves’ Disease Using Dose Corrected for Thyroid Gland Size

“…This figure was lower than reported in the previous studies using the estimation method to determine I-131 activity with the success rate between 60-85%. 10,11,[14][15][16][17][18] Several factors affected our therapeutic outcome. The first important factor that affected the outcome was thyroid gland size, well known to be an independent predictor of the response to I-131 therapy.…”