Endocrine Abstracts

Background: As radioiodine therapy is highly effective in curing Graves’ hyperthyroidism and toxic multinodular goitre, the assessment of its efficacy by rendering those patients euthyroid while avoiding the development of permanent hypothyroidism, is important.

Aim: To determine the current practice of radioiodine treatment provided at our trust, in line with the recommended guidelines of the Royal College of Physicians and also to compare our success rate with the published data.

Method: Retrospective data of 100 hyperthyroid patients who underwent radioiodine treatment during 2013 to 2017, were analysed. One year follow up clinical data was reviewed.

Results: Among them, 45% had Graves’ disease, 16% had multinodular goitre (MNG), 3% had toxic adenoma and 22% were hyperthyroidism of indeterminate aetiology. Median radioiodine dose used for Graves’ disease and MNG patients were 534MBq (range 530–560 MBq). Two third (78%) had their thyroid function tested on the day of treatment. The median duration for the first follow-up was 8 weeks (range 6–9 weeks). After radioiodine therapy, 17% of patients were rendered euthyroid (off the treatment for 1 year), whereas 83% became hypothyroid. The median duration for developing post radioiodine hypothyroidism was 10 weeks (range 6–34 weeks). Graves’ hyperthyroid patients (50%) had a higher incidence of developing post radioiodine hypothyroidism than MNG patients (34%). Sixteen patients had significant elevation of free T4 > 70pmol/L at the time of diagnosis and required a second dose of radioiodine.

Conclusion: Our audit demonstrated a high success rate approaching 100% for radioiodine treatment; higher than the published results (60–84%). This has largely motivated us to continue practicing the current integrated approach in managing individual hyperthyroid patients while facilitating close collaboration with general practitioners to ensure their long term standardised follow-up.