The Study Of Affecting Factors For ¹³¹I Treating Lymph Node Metastasis In Patients With Differentiated Thyroid Carcinoma

Objective:To explore and evaluate the affecting factors for the curative effect of ¹³¹I treating cervical lymph node metastasis in the patients with differentiated thyroid carcinoma after surgery.Methods:A total of 163 DTC sufferers were included in this study.All patients underwent total thyroidectomy surgery/subtotal thyroidectomy surgery and neck lymph node dissection in central or central and lateral neck regions.All patients underwent iodine-131 thyroid ablation after surgery.Rx-WBS and single-photon emission computed tomography/computed tomography（SPECT/CT）were performed 7-10 days after the first iodine-131 treatment.According to the results of nuclear medical imaging,the patients were divided into lymph node metastasis group and non-metastasis group,and the differences in various clinical features between the two groups were compared.All patients were followed up for 1 to 12 months after iodine-131 treatment.According to the results of the following Rx-WBS+SPECT/CT,41 patients with lymph node metastasis in Rx-WBS who had been treated with the next radioactive iodine-131,were divided into two groups:successful clearance group and unsuccessful clearance group.The differences in various clinical features between the two groups were compared and Receiver Operating Characteristic（ROC）can evaluate the optimal critical value for predicting successful clearance of metastatic lymph nodes.The patients were divided into the curative effect according to the criteria of efficacy response evaluation in the guidelines through the receiver operating characteristic（ROC）and the best critical value evaluation.Results:The mode of operation,whether lateral lymph node dissection and ultrasound before iodine therapy indicate lymph node metastasis in lymph node metastasis group and non-metastasis group difference was statistically significant（P<0.05）.Unilateral or bilateral primary tumor,risk stratification of recurrence,ps-Tg,the dose of iodine-131and the size,number and target/non-target ratio of metastatic lymph nodes were significantly different between the two groups（P<0.05）.The preablative stimulated thyroglobulin（ps-Tg）before radioactive iodine-131 treatment and the size of metastatic lymph node were independent influencing factors.The lymph node staging of tumor,the interval between surgery and the first iodine-131 treatment,the size and number of metastatic lymph nodes were significantly different among the three groups of curative effects of metastatic lymph nodes on iodine-131（P<0.05）.The optimal cut-off values of the shortest diameter and target/non-target ratio were 0.61 cm and 8.87,respectively.When the shortest diameter is less than 0.61 cm,the target/non-target ratio is less than8.87,and both meet or only meet one of them,the area under the ROC curve for predicting successful clearance of metastatic lymph nodes by iodine-131 were 0.900、0.820、0.777 and 0.902,respectively.The sensitivity were 92%,82%,61%and 98%,and the specificity were 88%、82%、94%and 82%,respectively.The areas under ROC curve with satisfactory efficacy in predicting the response of metastatic lymph nodes to iodine-131 were 0.877,0.815,0.806 and 0.886,respectively,the sensitivity were 85%,77%,66%and 96%,respectively,and the specificity were 91%,86%,95%and 81%,respectively.Conclusion:1.The mode of operation,lateral lymph node dissection and ultrasound display of lymph node metastasis before iodine-131 treatment were important factors affecting the detection of DTC metastatic lymph nodes by Rx-WBS.2.The total success rate of cervical lymph node ablation with iodine-131 was74.24%.For DTC patients with lymph node metastasis found after the first iodine 131treatment,the ablation success rate of iodine 131 retreatment can reach 86.67%.And the success rate of subsequent treatment was 47.62%.3.Unilateral or bilateral primary tumor,risk stratification of recurrence,ps-Tg,the dose of iodine-131 and the size,number and target/non-target ratio of metastatic lymph nodes were the affecting factors for the curative effect of iodine-131 treating cervical lymph node metastasis in the patients with differentiated thyroid carcinoma after surgery.4.The lymph nodes with the shortest diameter<0.61 cm and iodine-131target/non-target ratio<8.87 had the best iodine-131 clearance effect.