EVALUATION OF PATIENTS WITH REMISSION FOLLOWING RADIOACTIVE IODINE TREATMENT

A RETROSPECTIVE ANALYSIS

Abstract

INTRODUCTION
Prompt and appropriate management of thyrotoxicosis is important to prevent premature cardiovascular morbidity and mortality. In this respect, our experience with radioactive iodine therapy (RAI) has been very favourable with 85% achieving remission after six months. Nevertheless, the use of antithyroid drugs post-RAI has been suggested to be associated with hypothyroidism at one year. However, we do not use antithyroid drugs postRAI in our centre. We evaluated the characteristics of our patients who have remission after RAI.

METHODOLOGY
Participants were identified from the list of patients who underwent RAI therapy for thyrotoxicosis in our institution from January 2013 to April 2018. All the patients were referred for RAI following the failure of conventional antithyroid therapy to induce lifelong remission. Patients’ characteristics, clinical outcomes and laboratory results were analyzed from the medical and laboratory records. Descriptive statistics were used to describe the data. Relationships were explored with appropriate statistics with significant findings established at p<0.05.

RESULTS
A total of 168 patients were identified. Out of 142 (85%) patients who had remission, 58 (34.5%) were euthyroid while 84 (50%) have hypothyroidism within one-year postRAI. There is no association between RAI dose, age, gender, aetiology or day of administration of RAI.

CONCLUSION
Despite not using antithyroid post-RAI, remission rate remained high. Since remission is associated with significant hypothyroidism, determining the optimal time for initiating thyroxine replacement treatment is an important area for research.