The use of 132-I in the study of thyroid function shortly after 131-I treatment

The 2 hr. uptake of 132I was measured with a multi-channel analyser in thirty-four thyrotoxic patients, 3, 6 and 9 weeks after treatment with 131I, and the results were correlated with the clinical outcome assessed 3 months after treatment. Patients becoming euthyroid showed a lower mean uptake of 132I than those requiring further treatment. The difference was statistically significant at all three intervals, but there was a wide overlap of individual cases. It is concluded that radio-iodine tests shortly after treatment are of little value in predicting the eventual clinical outcome and in deciding whether additional treatment is required.