Endocrine Abstracts

Behavioural restrictions observed following Radioiodine therapy(RAI) administered for management of hyperthyroidism are becoming more stringent. Over the last two years we have administered a fixed 400 MBq RAI dose after performing a 24-hour RAI uptake test with a view to reducing post RAI restrictions e.g. for patients with a 50% uptake, restrictions applicable to 200 MBq were advised. The aim or our study was to compare the restrictions as advised by this method with what would have been advised if uptake test had not been performed. 53 patients were treated over the last 18 months with a fixed 400 MBq RAI dose. Mean age was 53 years, 43(81%) were females and mean uptake was 56%. Degree of reduction in restrictions is shown in the table. 15 randomly selected patients were visited at home, 24 hours after administration of the full RAI dose and uptake was calculated from the measured dose rate (mSv/hour) at one metre. In all cases the measured uptake of the test dose accurately predicted the calculated uptake of the total dose. Patient preference was sought between 2-day method incorporating the test dose with reduced restrictions with the 1-day method without test dose but with full restrictions. Only 3 patients(6%) preferred the 1-day method. In conclusion, we believe that RAI uptake prior to therapeutic RAI dose significantly and safely reduces the duration of post RAI restrictions and although it involves attending the hospital on two days, a majority of patients prefer this method.