The Clinical Value Of Serum TG And ¹³¹I-WBS On The Differentiated Thyroid Cancer After ¹³¹I Remnant Ablation

ObjectiveTo investigate the clinical value of serum thyroglobulin(TG) levels and 131I-whole body scan (131I-WBS) on the differentiated thyroid cancer (DTC) after 131I remnant ablation.MethodsBlood samples were taken for measurement of serum TG levels by chemiluminescence and 131I-WBS were performed using a single photon emission computed tomography(SPECT) in 64 DTC patients who had received near-total/total thyroidectomy and radioactive iodine remnant ablation. SPSS 13.0 program were used to analyse the data to estimate the clinical value of serum TG levels and 131I-WBS on the DTC after 13II remnant ablation.ResultsIn 64 patients with DTC, there were 33 patients who had serum TG concentrations< 2ng/ml (6 patients who have a positive 131I-WBS),10 patients who had serum TG concentrations of 2-10ng/ml (4 patients who have a positive 131I-WBS) and 21 patients who had serum TG concentrations>10ng/ml (19 patients who have a positive 131I-WBS). Among groups with different levels of serum TG, thyroid cancer recurrence or metastasis rate increased with TG elevation. There are significant differences in recurrence or metastasis rate between two groups (p<0.05). There are 31 patients whose TG>2ng/ml and 29 patients who have a positive 131I-WBS. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of measurements of TG in the detection of thyroid cancer recurrent or metastasis is 80.6%, 81.8%,81.3%,80.6% and 81.8% respectively. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of 131I-WBS in the detection of thyroid cancer recurrent or metastasis is 93.5%,100%,96.9%,100% and 94.3% respectively. After combining serum TG with 131I-WBS to detect thyroid cancer recurrent or metastasis, the sensitivity, specificity, accuracy, positive predictive value and negative predictive value is 100%,81.8%, 90.6%,83.8%, and 100% respectively.ConclusionThe serum TG and 131I-WBS play a major role in the DTC patients who had received near-total/total thyroidectomy and treated with 131I remnant ablation. The combination of serum TG and 131I-WBS has a higher diagnostic value than serum TG or 131I-WBS.