Results of PET dosimetry in the treatment of thyrotoxicosis by I-131

Despite its long history, there are many different approaches to the treatment of thyrotoxicosis with radioiodine. Our aim in this study is to increase the probability of achieving a euthyroid state with a single administration of I-131. The parameters, uptake, effective half-life and volume, needed to calculate the activity of radioiodine for treatment and the subsequent radiation dose achieved, are determined from a I-124 tracer study and PET scanning. Preliminary results suggest that using this regime there is an increase in the number of patients becoming euthyroid after a single treatment as compared to those who received a fixed activity of radioiodine.