ABSTRACT
Background and purpose:This study aimed to investigate the relationship between lymph node metastatic rate (LR) and response to radioiodine therapy in patients with papillary thyroid carcinoma (PTC).Methods:A total number of 143 PTC patients after radioiodine therapy were included and classified into 4 groups [Ⅰ(0%-10%),Ⅱ(>10%-25%),Ⅲ(>25%-50%),Ⅳ(>50%)] according to the lymph node metastatic rate, and the responses to initial radioiodine therapy after a median follow-up period of 20.7 months were evaluated. They were classiifed into 4 groups [excellent response (ER), indeterminate response (IDR), biochemical incomplete response (BIR), and struc-tural incomplete response (SIR)] according to the guideline proposed by 2015 American Thyroid Association. One-Way analysis of variance,χ2 test and Kruskal-Wallis test were used to evaluate the differences in basic clinicopathological features and clinical responses among the 4 groups. The ROC curve was analyzed to evaluate the clinical value of lymph node metastatic rate for predicting ER and optimal cut-off point.Results:There were no signiifcant differences in gender and T-stage among 4 groups (P>0.05). However,Ⅰ group was signiifcantly older than the other 3 groups (P=0.001). With the increase of lymph node metastatic rate, the number of ER cases decreased, while cases of BIR and SIR generally increased. Compared with the other 3 groups, less cases of ER (27.8%), while more BIR (27.8%) or SIR (11.1%) were observed in groupⅣ (H=18.816,P=0.000). Cut-off value of lymph node involved rate was 52.27%, with a better speciifcity of predicting ER. Area under the ROC curve was 0.668.Conclusion:The higher lymph node metastatic rate in patients with PTC, the worse clinical outcome it could be. A cut-off value of lymph node metastatic rate 52.27% is a speciifc independent predictor for the clinical outcome in PTC patients treated with radioiodine therapy.
ABSTRACT
PURPOSE: The purpose of this study was to evaluate if short-term serum thyroglobulin (Tg) elevation after radioiodine administration can predict successful radioiodine remnant ablation (RRA) and whether comparable RRA effectiveness is exhibited between a group administered with recombinant human thyrotropin (rhTSH) and a group experiencing thyroid hormone withdrawal (THW), in preparation for RRA. MATERIALS AND METHODS: A retrospective chart review was performed on 39 patients in the rhTSH group and 46 patients in the THW group. They were treated for differentiated thyroid carcinoma by total or near total thyroidectomy, and referred for RRA between 2003 and 2006 (the rhTSH group) and between January and June of 2006 (the THW group). They were assessed for serum Tg levels just before I-131 administration (TgD0), reassessed 9 days later (TgD9), and again 6-12 months later. RESULTS: RRA was successful in 64 (37 from the THW group and 27 from the rhTSH group) of the total 85 patients. The success rates of RRA had no statistically significant differences between the two groups. In both groups, TgD9/TgD0 values were significantly higher in the RRA success group (the rhTSH group; P=0.03, the THW group; P=0.04). By combining cutoff values of TgD0 and TgD9/TgD0, the successful RRA value was determined to be 96.7% (29/30) with TgD04.37 in both groups (the rhTSH group; 100% (16/16), the THW group; 92.9% (13/14)). Using logistic multivariate analysis, only TgD0 was independently associated with successful RRA. CONCLUSION: We may predict successful ablation by evaluating short-term serum Tg elevation after I-131 administration for RRA, in both rhTSH and THW patients.
Subject(s)
Humans , Multivariate Analysis , Retrospective Studies , Thyroglobulin , Thyroid Gland , Thyroid Neoplasms , Thyroidectomy , Thyrotropin , Thyrotropin AlfaABSTRACT
A low iodine diet (LID) for 1~2 weeks is recommended for patients who undergoing radioiodine remnant ablation. However, the LID educations for patients are different among centers because there is no concrete recommendation for protocol of LID. In this investigation, we compared two representative types of LID protocols performed in several centers in Korea using urine iodine to creatinine ratio (urine I/Cr). METHODS: From 2006, April to June, patients referred to our center for radioiodine remnant ablation of thyroid cancer from several local hospitals which had different LID protocols were included. We divided into two groups, stringent LID for 1week and less stringent LID for 2 weeks, then measured their urine I/Cr ratio with spot urine when patients were admitted to the hospital. RESULTS: Total 27 patients were included in this investigation (M:F=1:26; 13 in one-week stringent LID; 14 in two-week less stringent LID). Average of urine I/Cr ratio was 127.87+/-78.52 microgram/g in stringent LID for 1 week, and 289.75+/-188.24 microgram/g in less stringent LID for 2 weeks. It was significantly lower in stringent LID for 1 week group (p=0.008). The number of patients whose urine I/Cr ratios were below 100 microgram/g was 6 of 13 in stringent LID for 1 week group, and 3 of 14 in less stringent LID for 2 weeks group. CONCLUSION: Stringent LID for 1 week resulted in better urinary I/Cr ratio in our investigation compared with the other protocol. However it still resulted in plenty of inadequate range of I/Cr ratio, so more stringent protocol such as stringent LID for 2 weeks is expected more desirable.