Is There Any Need for Adjusting 131 I Activity for the Treatment of High Turnover Graves’ Disease Compared to Normal Turnover Patients? Results from a Retrospective Cohort Study Validated by Propensity Score Analysis
10.1007/s13139-020-00674-3
- Author:
Saurabh ARORA
1
;
Chandrasekhar BAL
Author Information
1. Department of Nuclear Medicine, All India Institute of Medical Sciences, New Delhi 110029, India
- Publication Type:ORIGINAL ARTICLE
- From:Nuclear Medicine and Molecular Imaging
2021;55(1):15-26
- CountryRepublic of Korea
- Language:English
-
Abstract:
Purpose:To compare 131I-therapy outcomes in high turnover and normal turnover Graves’ disease patients and predict optimal first 131I activity for high turnover patients.
Methods:Retrospective cohort design (1:2) validated by propensity score analysis. Cohort 1, high turnover (2-h RAIU/24-h RAIU ≥ 1), n = 104, and cohort 2, normal turnover (ratio < 1), n = 208, patients were compared for post 131I outcome. The cure was defined as a combined euthyroid and stable hypothyroid state following 131I treatment. Logistic regression analysis was used for identifying prognostic factors. The propensity score was applied; 77 matched pairs (1:1 ratio) of high and normal turnover patients were selected as a validation set.
Results:First 131I cure rates of 28% in high turnover and 66% in normal turnover groups (p = 0.001) were noted. The therapy cycles (median, 2 vs. 1) and cumulative 131I activity (median, 15 vs. 7 mCi) were required to cure hyperthyroidism in cohort 1 and cohort 2, respectively. Age (> 44 years), higher grade of goitre, and 2-h RAIU (> 37%) were associated with 131I therapy failure.The high turnover patients needed a factor of 1.5–2 times more 131I activity to achieve a similar cure rate compared to the normal turnover patients. The first-dose cure rate was 31% vs. 60% by propensity score analysis (n = 154), no way different (28% vs.66%) from the whole group of 312 patients.
Conclusion:High turnover Graves’ disease patients, if administered standard 131I activity, the outcomes shall be poor. To improve the success rate, 131I activity should be increased by 1.5 to 2 times in the high turnover patients.
