Efficacy Analysis And Prediction Model Establishment Of ¹³¹I In Intermediate-to-high Risk DTC Patients With HT

Objective:We analyzed the factors that affected the efficacy of ¹³¹I in intermediate-to-high risk DTC patients who combined with HT and established a prediction model and explored its value based on clinical data and biochemical marks before and after ¹³¹I therapy and their dynamic changes.Methods:We retrospectively analyzed 327 postoperative DTC patients who had their first ¹³¹I therapy and matched the inclusion and exclusion criteria in the Department of Nuclear Medicine,First Hospital of Shanxi Medical University between September 2017 and December 2020,collected clinical,pathological and biochemical test data of the study subjects before ¹³¹I therapy,obtained laboratory test results of the patients around 1 month,3 months and 1 year after ¹³¹I therapy through follow-up,and calculated to obtain dynamic change indicators.Using postoperative pathological test results as the gold standard,patients were divided into two groups:the non-HT group and the HT group.Patients were stratified for risk of recurrence according to the 2015 ATA guidelines and given 1.1 GBq-7.4 GBq（30m Ci-200 m Ci）¹³¹I treatment with strict adherence to a low iodine diet for 1 month prior to treatment,discontinuation of levothyroxine sodium tablets for at least 4 weeks,and 100-150ug levothyroxine sodium tablets suppression therapy 2 days after the first ¹³¹I therapy,followed by 2-5 days of ¹³¹I therapy followed by whole body imaging.The treatment efficacy of patients was evaluated after 1 year of follow-up,and patients were divided into two groups according to the efficacy assessment,ER group and non-ER group（including IDR,BIR,and SIR）.The Mann-Whitney U test and chi-square test were used to analyze the differences between groups,and P<0.05 was considered statistically significant;LASSO-Logistic was used to analyze the risk factors affecting the efficacy of ¹³¹I therapy in the HT group,and construct an efficacy prediction model and draw ROC curves and column line graphs to evaluate the model efficacy by AUC values,accuracy and sensitivity.Results:There were statistical differences in risk of recurrence stratification,TPOAb,Tg Ab,FT₄,s Tg,FT₃/FT₄,s Tg/TSH,cumulative dose and efficacy between patients in the HT and non-HT groups before ¹³¹I therapy（P<0.05）.The efficacy of ¹³¹I therapy was better in the non-HT group than in the HT group（χ2=4.038,P=0.044）.There was no statistical difference in gender,age,tumor size,extra-glandular invasion,lymph node metastasis,distant metastasis,FT₃ level and TSH level before ¹³¹I therapy between the two groups（P>0.05）.The LASSO was used to screen the influencing factors affecting the efficacy of ¹³¹I therapy in the HT group,and the final five indices obtained were age,Tg Ab and s Tg before¹³¹I therapy,ΔTPOAb andΔTg.The five indices obtained from the screening were used to construct a logistic regression model,and the ROC curve was used to assess their efficacy prediction efficacy,and the AUC value was 0.90（95%CI 0.84-0.96）,an accuracy rate of84.0%,a sensitivity rate of 82.0%and a specificity rate of 72.5%,and a line graph was plotted with the above indicators.Conclusion:The intermediate-to-high risk DTC Patients with HT had significantly lower benefits than those DTC patients who were not associated with HT.The ages,Tg Ab and s Tg before the first ¹³¹I therapy,TPOAb and Tg change rate of DTC patients with HT were the influential factors affecting the efficacy of ¹³¹I therapy,and the constructed prediction model and column line graph had high predictive value.