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

BACKGROUND: Radioactive 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. METHODS: Data 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. RESULTS: Of 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%). CONCLUSION: Radioiodine 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.

The Utility of 99mTc-DPD Scintigraphy in the Diagnosis of Cardiac Amyloidosis: An Australian Experience.

BACKGROUND: The uptake of bone-seeking radiotracers in the amyloid heart is well recognised. 99mTc-DPD has been shown to be highly sensitive for cardiac transthyretin (ATTR) amyloid in an overseas population, but is not registered for use in Australia. We explored its utility as a diagnostic tool within our population. METHODS: Patients diagnosed with AL and ATTR (wild-type and inherited) cardiac amyloidosis were prospectively recruited from the Princess Alexandra Hospital Amyloidosis Centre. Patients underwent injection with 99mTc-DPD then planar whole body imaging was performed at 5 minutes post-injection (soft tissue phase) and 3 hours (bone phase). A myocardial SPECT and low amperage CT were acquired after the late whole-body scan. Scans were analysed by two nuclear imaging specialists. Intensity of cardiac 99mTc-DPD uptake was graded as 0 to 3 in accordance with previous criteria, and semiquantitative analysis was performed using a heart to whole body ratio (H:WB) on the 3-hour scan. Patients also underwent electrocardiography and transthoracic echocardiography, and blood samples were taken for troponin I and brain natriuretic peptide levels, to assess for any correlation with DPD uptake. RESULTS: Twenty-one patients (8 AL and 13 ATTR) completed the study. Median age was 58 and 70 years for AL and ATTR patients respectively, and 19 (90.5%) were male. 99mTc-DPD scintigraphy was positive in 2 (25%) of AL, and 13 (100%) of ATTR patients. Grade of cardiac uptake, and mean H:WB (0.1249 v. 0.0794) was greater in the ATTR cohort (p-value<0.001 and 0.001 respectively). No statistically significant correlation was identified between H:WB and echocardiographic parameters. There was a significant positive correlation between H:WB and the PR interval on ECG (p=0.026). CONCLUSIONS: 99mTc-DPD scintigraphy is highly sensitive for the diagnosis of cardiac ATTR amyloid, but less so for AL amyloid.

Are Australian children iodine deficient? Results of the Australian National Iodine Nutrition Study.

OBJECTIVE: To document the population iodine nutritional status in Australian schoolchildren. DESIGN AND SETTING: Cross-sectional survey of schoolchildren aged 8-10 years, based on a one-stage random cluster sample drawn from all Year 4 school classes in government and non-government schools in the five mainland Australian states of New South Wales, Victoria, South Australia, Western Australia and Queensland. The study was conducted between July 2003 and December 2004. PARTICIPANTS: 1709 students from 88 schools (881 boys and 828 girls), representing 85% of the estimated target number of students. The class participation rate was 65%. MAIN OUTCOME MEASURES: (i) Urinary iodine excretion (UIE) levels (compared with the criteria for the severity of iodine deficiency of the World Health Organization/International Council for the Control of Iodine Deficiency Disorders: iodine replete, UIE > or = 100 microg/L; mild iodine deficiency, UIE 50-99 microg/L; moderate iodine deficiency, UIE 20-49 microg/L; severe iodine deficiency, UIE < 20 microg/L); (ii) Thyroid volumes measured by ultrasound (compared with new international reference values). RESULTS: Overall, children in mainland Australia are borderline iodine deficient, with a national median UIE of 104 microg/L. On a state basis, NSW and Victorian children are mildly iodine deficient, with median UIE levels of 89 microg/L and 73.5 microg/L, respectively. South Australian children are borderline iodine deficient, with a median UIE of 101 microg/L. Both Queensland and Western Australian children are iodine sufficient, with median UIE levels of 136.5 microg/L and 142.5 microg/L, respectively. Thyroid volumes in Australian schoolchildren are marginally increased compared with international normative data obtained from children living in iodine sufficient countries. There was no significant association between UIE and thyroid volume. CONCLUSION: Our results confirm the existence of inadequate iodine intake in the Australian population, and we call for the urgent implementation of mandatory iodisation of all edible salt in Australia.

6: Thyroid nodules and thyroid cancer.

Thyroid nodules are common clinically (prevalence, about 5%) and even more common on ultrasound examination (about 25%). About 5% of thyroid nodules are malignant. Most thyroid cancers are well-differentiated papillary or follicular tumours with an excellent prognosis (10-year survival, 80%-95%). The incidence of papillary thyroid cancer appears to be increasing on the east coast of Australia. Fine-needle aspiration biopsy of the thyroid is the most cost-effective diagnostic tool. Recommended initial management of all follicular carcinomas and of papillary carcinomas > 1.0 cm is total thyroidectomy followed by radioiodine ablation. Most patients should be managed postoperatively with doses of thyroid hormone sufficient to suppress plasma levels of thyroid-stimulating hormone. Recurrences can occur many years after initial therapy, and follow-up should be lifelong. Thyroid nodules are very common, but have a relatively low risk of malignancy