Comparison between ablation efficacy of 1. 1 GBq and 3. 7 GBq 131I for low- and intermediate-risk differentiated thyroid carcinoma / 中华核医学与分子影像杂志

ABSTRACT

Objective To compare the ablation efficacy and therapy response with 1. 1 GBq and 3. 7 GBq 131I in postoperative patients with low- and intermediate-risk differentiated thyroid carcinoma (DTC). Methods A total of 190 patients (43 males, 147 females, age(45.8±11.1)years) were enrolled from July 2016 to July 2017. Among them, 96 patients received 1.1 GBq 131I and 94 were given 3.7 GBq 131I. Diagnostic whole-body scan was performed 6 months after 131 I ablation for treatment response evaluation, and the successful rate of 131I ablation was calculated. χ2 test or Fisher's exact test was used for data analysis. The cut-off value of 99 Tcm-pertechnetate uptake for predicting the successful rate of remnant thyroid ablation in 1.1 GBq group was determined by receiver operating characteristic ( ROC) curve analysis. Results The successful ablation rates in 1.1 GBq and 3.7 GBq groups were 79.2％(76/96) and 81.9％(77/94), respec-tively (χ2=0.229, P>0.05). There was no significant difference in the therapy response between the two groups (χ2=1.371, P>0.05) . The successful ablation rate in 3.7 GBq group was higher than that in 1.1 GBq group for patients with stageⅢ(5/6 vs 1/7, P=0.029). Moreover, for patients with 5μg/L<preablative-stimula-ted thyroglobulin (ps-Tg)≤10μg/L, the ablation rate in 1.1 GBq group was lower than that in 3. 7 GBq group ( 3/11 vs 10/13, P=0.038) . ROC curve analysis showed the cut-off value of 99 Tcm-pertechnetate uptake for prediction of the successful ablation rate in 1.1 GBq group was 0. 0615. Conclusion The low- and inter-mediate-risk DTC patients with stageⅢdisease, 5μg/L<ps-Tg≤10μg/L or higher 99 Tcm-pertechnetate up-take of remnant thyroid should be given 3.7 GBq other than 1.1 GBq 131I to obtain a better ablation efficacy.