Analysis Of The Efficacy And Influential Factors Of ¹³¹I Thyroid Remnant Ablation On DTC After Operation

Objective:The main purpose of this study is to to evaluate the clinical efficacy and analyze the risk factors of ¹3131 I treatment for thyroid remnant ablation in patients with differentiated thyroid cancer?DTC?after operation.Methods:During the period from June 2015 to December 2017,360 patients who underwent¹³¹I treatment in our hospital were collected.All patients were treated with 3.7 GBq?100mCi?of ¹³¹I for the first time after treatment.After an average of 6 months,¹³¹I was performed again,and whole body imaging was performed 5-7 days later.Refer to the2015 US ATA^[1]guidelines recommended for the thyroid remnant ablation standard,evaluate the efficacy of the first ¹³¹I treatment for thyroid remnant ablation,and analyze the effects of various factors on the effect of the first ¹³¹I.Univariate analysis and multivariate logistic regression were used to analyze gender,age,case histology,tumor size,lymph node metastasis,distant metastasis,Hashimoto thyroiditis?HT?,unilateral or bilateral lesions,TNM staging,stratification of recurrence risk,time to ¹³¹I for the first operation,serum TSH level before clearing,sTg/TSH and pre-clear thyroglobulin?sTg?.Univariate analysis was used to analyze the significant factors and binary logistic regression analysis was carried out.The ROC curve of the statistical factors will be established to obtain the best diagnostic threshold.With P<0.05 as the difference,there is statistical significance.Results:1.The success rate of the first ¹3131 I thyroid remnant ablation was 66.7%?240/360?.2.Univariate analysis showed that the primary tumor diameter were lower in successful radioactive iodine remnant ablation groop than unsuccessful groop?P<0.05?;Gender has an impact on the success rate ofthe first ¹3131 I ablation?P<0.05?;The sTg level and sTg/TSH of the successful radioactive iodine remnant ablation groop was significantly lower than that of the unsuccessful group?P<0.05?;the successful rate is higher in low risk of recurrence group than intermediate and high risk of recurrence groups?P<0.05?;The success rate was without metastasis group is higher than that of the metastatic group,and the difference was statistically significant?P<0.05?.DTC patients with Hashimoto's thyroiditis and without Hashimoto's thyroiditis had no significant difference in the success rate of ¹3131 I ablation?P>0.05?.3.Multivariate logistic regression analysis showed that the primary tumor diameter?Wald=10.359,P=0.001?,pre-clear sTg?Wald=8.216,P=0.004?,lymph node metastasis?Wald=6.981,P=0.008?and far The metastasis?Wald=4.001,P=0.007?were crucial factors affecting the efficacy of the first ¹3131 I ablation after surgical treatment of DTC.4.Areas under receiver operating characteristic curves for sTg,and tumor size to predict unsuccessful ablation were 0.787,0.796,and 0.535respectively.The threshold values were 4.035ng/ml,0.041mg/iu,and1.950cm,respectively.The sensitivities were86.20%,89.20%,and 64.92%and the specificities were 63.10%,63.60%,and53.40%,respectively.Conclusion:1.The efficacy of the first ¹3131 I thyroid remnant ablation after surgical treatment of DTC is well demonstrated.2.The tumor size,pre-ablation sTg,sTg/TSH,lymph node,and distant metastases are crucial factors affecting its efficacy.3.The sTg level and sTg/TSH ratio before the first ¹3131 I thyroid remnant ablation are good indicators for predicting the efficacy of thyroid remnant ablation.