Poster Abstract Abstract
(Adults - Thyroid), #220531294302
PREDICTIVE FACTORS FOR FAILURE OF FIRST RADIOACTIVE IODINE (RAI) THERAPY IN PATIENTS WITH HYPERTHYROIDISM
Tilagamaty Murthy, University Malaya Medical Centre; Shubash Shander, Institute for Public Health, National Institute of Health, Ministry of Health Malaysia; Jeyakantha Ratnasingam, University Malaya Medical Centre; Lee Ling Lim, University Malaya Medical Centre; Shireene Vethakkan, University Malaya Medical Centre; Sharmila Paramasivam, University Malaya Medical Centre
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Radioactive iodine (RAI) therapy is used commonly and successfully as a definitive treatment for hyperthyroidism. Predictive factors for RAI outcome have previously shown to be heterogenous. This study was aimed to examine the prevalence of treatment failure at 1 year post RAI as well as identify the predictors of RAI failure in our local urban population.
This was a retrospective study involving patients who had undergone first RAI therapy from January 2015 to December 2020 in UMMC. Pre-RAI and post-RAI data was collected from electronic medical records (EMR) including demographics, goiter size, TFT at diagnosis/pre-RAI, RAI dose, anti-thyroid drug duration/dose and time taken to achieve euthyroidism or hypothyroidism. The data was then analyzed using SPSS version 23 as mean/median or frequencies with multivariate analysis done using logistic regression.
A total of 292 patients were included in the study. Majority of the patients were female (69.9%) with Grave’s disease (79.2%). The median radioiodine dose given was 16mCI (10,18). 85.3% of patients achieved treatment success within one year of RAI, with 93.2% of them achieving success within 6months. Only 43(14.7%) had RAI treatment failure as they had persistent hyperthyroidism one-year post-RAI. We found that a high serum free T4 at diagnosis was a predictive factor for RAI failure (OR 1.01,95% CI 1.01 – 1.02, p value = 0.002). There was no significant association between age, gender, BMI, goiter size and RAI dosage with failure of RAI in our study population.
High serum free T4 on diagnosis was associated with poorer RAI outcomes, hence this should be taken into consideration when planning for RAI therapy, where patients may need to be considered for higher doses of RAI or thyroidectomy if indicated.