Analysis Of Factors Related To The Efficacy Of ¹³¹I Therapy In Patients With Graves’ Disease

Objectives:To explore the efficacy and influencing factors of radioactive iodine131（RAI）in the treatment of Graves’disease（GD）,to analyze the incidence of hypothyroidism after radioactive iodine 131 therapy for Graves’disease,and to explore the indexes to predict the occurrence of hypothyroidism and ineffective treatment,so as to provide a theoretical basis for improving the success or remission rate of clinical ¹³¹I treatment.Methods:In a retrospective study,patients with Graves’disease who were treated with radioactive iodine in the Department of Endocrinology and Nuclear Medicine of Hunan people’s Hospital from January 2015 to January 2020 were followed up from January 2019 to January 2021.The data were analyzed by SPSS21.0 statistical software and Logistic model fitting for multivariate analysis.The predictive cutoff point was determined by ROC diagnostic curve and the index was evaluated.P<0.05 was considered statistically significantly difference.Results:1.The total effective rate of GD patients treated with radio-iodine 131was 79.6%,of which the remission rate was 38.4%,the incidence of hypothyroidism was 41.2%,and the ineffective rate was 20.4%.2.Univariate analysis showed that there were no significant di-fferences in age,sex,duration of ATD use,Body Mass Index（BMI）,Free triiodothyronine（FT₃）,Free thyroxine（FT₄）,Thyroid Stimulating Hormone（TSH）,Alanine transaminase（ALT）,Aspartate aminotransferase（AST）,Serum creatinine（SCr）,White blood cell count（WBC）,Percentage of neutrophils（N%）and thyroid nodules among different therapeutic effects（P>0.05）.There were significant differences in the course of disease,oral ATD,thyroid autoantibody,thyroid iodine uptake rate,thyroid mass and radioiodine content perunit thyroid tissue among different therapeutic effects（P<0.05）.3.The results of multivariate logistic regression analysis showed that the course of disease,thyroperoxidase antibody（TPOAb）,24-hour Radioactive iodine uptake（24h RAIU）,thyroid mass and radioiodine content perunit thyroid tissue were the key factors affecting the curative effect.Compared with the inefficacy of treatment,there was a significant positive correlation between TPOAb and remission efficacy,a significant negative correlation between the course of disease and 24-hour Radioactive iodine uptake and remission efficacy.The shorter the course of disease,the higher the TPOAb,the lower the 24-hour Radioactive iodine uptake,the smaller the thyroid mass and the higher the unit dose,the higher the probability of hypothyroidism.4.The ratio of FT₃ after 3 months of radioactive iodine 131 treatment to FT₃ before treatment（3^mFT₃/0^mFT₃）is less than 0.218,The sensitivity for predicting the occurrence of hypothyroidism after ¹³¹I treatment in Graves’disease is 58.6%and the specificity is 76.6%;after 3 months the ratio of FT₄ to FT₄ before treatment（3^mFT₄/0^mFT₄）is less than 0.254,and the sensitivity for predicting hypothyroidism after ¹³¹I treatment in Graves’disease is 59.8%and the specificity is 81.5%.5.The 24-hour iodine uptake rate is more than 73.5%,the sensitivity for predicting the ineffectiveness of ¹³¹I treatment for Graves’disease is51.2%,and the specificity is 83.9%.Conclusions:1.Radioiodine 131 therapy is safe and effective in the treatment of GD with few side effects,and the total effective rate is 79.6%.The course of disease,TPOAb,24-hour Radioactive iodine uptake,thyroid mass and radioiodine content perunit thyroid tissue were the key factors affecting the curative effect.2.Early-onset hypothyroidism mostly occurs 3-6 months after treatment,and its thyroid hormone level decreases most significantly in the first month.The ratio of FT₃、FT₄ to pre-treatment FT₃、FT₄ at 3months after radioiodine treatment（3^mFT₃/0^mFT₃、3^mFT₄/0^mFT₄）can be used as a reference index to predict whether hypothyroidism will occur,and the predictive cut-off points are<0.218 and<0.254,respectively.3.The 24-hour Radioactive iodine uptake rate has a certain value in predicting the ineffectiveness of GD radioactive iodine 131 treatment,and the predictive cut-off point is>73.5%.