The Retrospective Study Of Clinical Characteristic And Classification In TENIS Syndrome And Valuation Of The Efficacy Of Radioiodine Therapy

Background:For differentiated thyroid cancer(DTC)patients with thyroglobulin(Tg)elevation and negative iodine scintigraphy(commonly termed "TENIS"syndrome)after thyroidectomy,radioactive iodine(RAI)therapy,and thyroid-stimulating hormone(TSH)suppression therapy,empirical RAI therapy may be considered.TENIS syndrome has become an urgent issue to be solved in the clinical management of DTC,but the diagnosis standards and treatment schemes of these patients have not reached consensus yet.This article will discuss the classification of TENIS syndrome,explore the clinical characteristics and risk factors,and provide treatment strategies with these patients.We assessed the clinical characteristics in TENIS syndrome and the empirical RAI therapy in TENIS syndrome with the biochemical incomplete remission and evaluated the progression-free survival(PFS).Methods:This study was approved by the Ethics Committee of Zhujiang Hospital of Southern Medical University.A total of 290 patients with TENIS syndrome were included in this retrospective study in nuclear medicine department from April 2014 to April 2017 and divided into the structural incomplete remission group and the biochemical incomplete remission group of TENIS syndrome.The progression-free survival of both groups was defined as the main outcome.Secondary outcomes were:the comparison of serum Tg level 12 months after being diagnosed as TENIS syndrome.A suppressed Tg value<0.2 ng/ml and a decrease>50%was defined as accepted remission(AR).Results:Among the TENIS syndrome patients,168(57.9%)were female.Papillary Thyroid Cancer(PTC)was the main pathological type,including classic and follicular subtypes in 276(95.2%)cases.Follicular carcinoma was 8(2.8%)cases,and 6(2.1%)cases of other pathological types.Intermediate-risk patients accounted for 95.7%,and 147(57.6%)patients had more than 5 metastatic lymph nodes.154 patients in the structural incomplete remission group of TENIS syndrome and 136 patients in the biochemical incomplete remission group.Differences in age(χ2=10.879,p=0.001),tumor size(χ2=11.414,p=0.003),multifocality(χ2=9.338,p=0.002),8th AJCC stage(χ2=8.619,p=0.035)between the two groups The difference is statistically significant.Multifocality(OR=2.507,95%CI:1.238-5.076)was risk predictors of structural incomplete response.The PFS of the empirical RAI therapy group was better than the untreated group(p=0.001).Moreover,there was significant difference in AR between the two groups(p=0.025).Empirical RAI therapy(p=0.001)and fewer metastatic lymph nodes(LNMs)(p=0.014)predict the better PFS.There was a statistically significant difference between the two groups in whether serum Tg levels could reach AR status at 12 months after diagnosis of TENIS syndrome(p=0.025).Gender(p=0.003),LNMs(p=0.047),empirical RAI therapy(p=0.007)predict better remission in serum Tg level.Conclusion:The majority of patients with TENIS syndrome were female.Papillary carcinoma was the main pathological type.Intermediate-risk patients accounted for the majority(84.8%),and about half(50.7%)had LNMs≥5.Larger tumor size,multifocality,and higher ATA recurrence risk gr in 2015 were all risk factors for the clinical phenomenon of incomplete structural remission of TENIS syndrome.Patients with TENIS syndrome without structural disease can benefit from empirical RAI therapy in both PFS and Tg normalization.