ABSTRACT
Objective:To explore the value of pre-ablation stimulated thyroglobulin (psTg) before 131I treatment combined with lymph node ratio (LNR) in predicting 131I treatment response in patients with papillary thyroid cancer (PTC). Methods:From January 2016 to December 2018, 178 PTC patients (47 males, 131 females; age (43.2±12.6) years) treated with 131I in the Affiliated Cancer Hospital of Zhengzhou University were retrospectively analyzed. According to 131I treatment response, patients were divided into excellent response (ER) group and non-ER group. The clinical data of the two groups were compared by χ2 test, independent-sample t test and Mann-Whitney U test. The cut-off values and AUCs of psTg and LNR to predict treatment response were calculated according to the ROC curve. Factors affecting 131I treatment response were analyzed by logistic multivariate regression analysis. Results:There were 118 patients (66.3%, 118/178) in ER group and 60 patients (33.7%, 60/178) in non-ER group, and there were significant differences in N stage ( χ2=11.15, P=0.004), 131I treatment dose ( χ2=12.65, P<0.001), American Thyroid Association (ATA) initial risk stratification ( χ2=15.25, P<0.001), number of metastatic lymph nodes ( χ2=22.63, P<0.001), LNR ( U=1 506.00, P<0.001) and psTg ( U=919.00, P<0.001) between the two groups. The cut-off values of psTg and LNR predicting ER were 3.97 μg/L and 0.29, with the AUC of 0.870 and 0.787 respectively. PsTg (odds ratio ( OR)=10.88, 95% CI: 4.67-25.36, P<0.001) and LNR ( OR=5.30, 95% CI: 1.85-15.23, P=0.002) were independent factors to predict 131I treatment response in PTC patients. When psTg≥3.97 μg/L, LNR ( OR=9.40, 95% CI: 2.06-42.92, P=0.004) was an independent factor affecting 131I treatment response in PTC patients. Conclusions:PsTg and LNR are independent factors affecting 131I treatment response in PTC patients. When psTg≥3.97 μg/L, LNR can be used as a supplementary factor to predict 131I treatment response. The combination of psTg and LNR can better predict 131I treatment response in PTC patients.