Analysis of therapeutic response of iodine positive metastasis lymph nodes in differentiated thyroid cancer after 131I treatment

Background and purpose: Lymph node metastasis (LNM) is the most common metastasis of differentiated thyroid cancer (DTC), and the efficacy of 131I on LNM is controversial. The aim of this study was to clarify the efficacy of 131I on LNM with good iodine uptake and the influencing factors. Methods: In this study, 161 iodine positive metastasis lymph nodes from 90 DTC patients treated by 131I from January 2015 to June 2019 in Xinhua Hospital Affiliated To Shanghai Jiao Tong University School of Medicine were included, and the clinical and imaging data of the patients were analyzed. SPSS 24.0 software was used to make statistical analysis. The measurement data were distributed according to the normal distribution, then the independent sample t-test was compared. The comparison of the counting data was conducted by χ2 test, and the multivariate analysis was carried out by logistic regression analysis. The receiver operating characteristic (ROC) curve between multiple quantitative indexes and the failure of 131I treatment were established, and the optimal diagnostic threshold was obtained. Results: Among 161 iodine positive metastasis lymph nodes, 71 (44.10%) were effective, and 90 (55.90%) were ineffective. Univariate analysis showed that there were significant differences in age, gender, pathological type, number of primary lesions, location of primary lesions, distant metastasis and serum thyroglobulin (Tg) level between the two groups (P