Analysis On Correlation Of Thyroglobulin With Relevant Parameters Of ¹³¹I-WBS In Differentiated Thyroid Carcinoma Patients

Objective:Differentiated thyroid cancer is one of the most common malignant tumors in the clinical practice.The therapeutic regimen of TDC mainly includes the surgical treatment+ ¹³¹I therapy after surgery + thyroid stimulating hormone（TSH） suppression therapy. This study is to evaluate the correlation of thyroglobulin（Tg） with relevant parameters of ¹³¹I-whole body scan(¹³¹I-WBS) in differentiated thyroid carcinoma（DTC） patients after ¹³¹I administration and to provide reference index for judging recurrence and metastasis of DTC.Methods:DTC patients who had undergone thyroidectomy and accepted repeated ¹³¹I treatment during the period from 2011-01-11 to 2015-04-13 in the Nuclear Medicine Department of Shandong Cancer Hospital were reviewed, and then 117 patients(193 times ¹³¹I therapies) were enrolled in this study. The materials such as nuclear medicine imaging、clinical information、imaging data、serum Tg levels during the same period were collected and analyzed. The patients who undergone total thyroidectomy or subtotal resection accepted the radioactive ¹³¹I internal radiation therapy, oral doses of Na¹³¹I was 3.7-5.6GBq/times, and then ¹³¹I-WBS were performed after 5-7days. By the use of regions of interest（ROI） on ¹³¹I-WBS image, lesions radioactive counts（L）and ¹³¹I-WBS total radioactive counts（T）were measured, the same as physiological uptake（P）, bladder（B）and contaminated area（C）radioactive counts. Then the lesions radioactive counts ratio（R）was calculated, R=L/（T-P-B-C）. The patients were divided into seven groups（Group A-G） according to the ¹³¹I therapy times, the data were analyzed using SPSS V17.0, spearman and pearson coefficient were adopted to analyze the correlation between R and Tg.Resluts:1.The result of all 193 therapies was that R has positive correlation with Tg（rs=0.214,P<0.05）. For the first two groups, R showed significant positive correlation with Tg（r1=0.303,r2=0.388, P<0.05）. But for the last five groups, there was no correlation between R and Tg（P>0.05）.2.Furthermore, after removing the 47 therapies which R and Tg are inconsistent（R+Tgor R-Tg+）, the remaining 146 therapies revealed that there was significant positive correlation between R with Tg（rs’ =0.328,P<0.01）. For the seven groups, the results were similar with the above（group 1-2: r1’=0.327, r2’=0.694, P<0.05; group 3-7: P>0.05）.Conclusions:1.There was a positive correlation between serum Tg level and R during the early stage, so that the combined measurement of the two methods for monitoring recurrence and metastatic lesions is of important clinical value. But after several times’ treatments, R had no correlation with Tg, the clinical reference value declines.2.For the 47 therapies which R and Tg are inconsistent, they should be analyzed according to the clinical setting.3.It is important to detect Tg as well as TgAb.4.Further research and study of the relationship between Tg, R and TgAb in the ¹³¹I treatment of DTC patients are still needed.