Hu Hou-Yang, Liang Jun, Zhang Teng, Zhao Teng, Lin Yan-Song
Department of Nuclear Medicine, Peking Union Medical College Hospital.
Department of Oncology, the Affiliated Hospital of Qingdao University, Qingdao, China.
Nucl Med Commun. 2018 Mar;39(3):247-251. doi: 10.1097/MNM.0000000000000796.
According to the American Thyroid Association guidelines in 2015, both an unstimulated thyroglobulin (u-Tg) below 0.2 ng/ml and a stimulated thyroglobulin (s-Tg) below 1.0 ng/ml were required along with negative imaging findings to define an excellent response. This study aimed to investigate whether a u-Tg below 0.2 ng/ml coincides with a s-Tg below 1 ng/ml.
A total of 290 patients with nonmetastatic differentiated thyroid cancer were retrospectively evaluated with a median follow-up of 36 months. The levels of s-Tg were observed in patients whose u-Tg levels were below 0.2 ng/ml after radioiodine therapy, and risk factors associated with the increase of s-Tg to above 1 ng/ml from below 0.2 ng/ml were analyzed.
In total, 52.8% (153/290) of the patients achieved a u-Tg below 0.2 ng/ml 3 months after remnant ablation, most of whom (83.7%, 128/153) also achieved a s-Tg below 1 ng/ml. A total of 25 (16.3%) patients had an increased s-Tg above 1 ng/ml. A comparative analysis showed no significant difference between patients who showed an increase in thyroglobulin from below 0.2 ng/ml to above 1 ng/ml and those who did not. In a subgroup analysis assessing the influence of thyrotropin (thyroxin-stimulating hormone) on s-Tg, we enrolled 43 patients with at least two s-Tg measurements. We found that a higher level of thyroxin-stimulating hormone (118.23±30.72 vs. 59.99±26.12 µIU/ml) increased the s-Tg in 88.4% patients (P=0.00), which led to more patients (18.6-30.2%) with an increased s-Tg (to above 1 ng/ml) after thyroxin withdrawal.
Assessment of the level of u-Tg might be a better parameter to use for defining excellent response as u-Tg is more stable, convenient, economical, and is not associated with hypothyroidism as a side effect.
根据2015年美国甲状腺协会指南，要确定为极佳反应，需同时满足未刺激状态下甲状腺球蛋白（u-Tg）低于0.2 ng/ml、刺激状态下甲状腺球蛋白（s-Tg）低于1.0 ng/ml以及影像学检查结果为阴性。本研究旨在调查u-Tg低于0.2 ng/ml是否与s-Tg低于1 ng/ml相符。
对290例非转移性分化型甲状腺癌患者进行回顾性评估，中位随访时间为36个月。观察放射性碘治疗后u-Tg水平低于0.2 ng/ml的患者的s-Tg水平，并分析s-Tg从低于0.2 ng/ml升高至高于1 ng/ml的相关危险因素。
共有52.8%（153/290）的患者在残余甲状腺消融术后3个月时u-Tg低于0.2 ng/ml，其中大多数（83.7%，128/153）患者的s-Tg也低于1 ng/ml。共有25例（16.3%）患者的s-Tg升高至高于1 ng/ml。对比分析显示，甲状腺球蛋白从低于0.2 ng/ml升高至高于1 ng/ml的患者与未升高的患者之间无显著差异。在一项评估促甲状腺激素（甲状腺素刺激激素）对s-Tg影响的亚组分析中，我们纳入了43例至少进行过两次s-Tg测量的患者。我们发现，较高水平的甲状腺素刺激激素（118.23±30.72对59.99±26.12 μIU/ml）使88.4%的患者s-Tg升高（P = 0.00），这导致更多患者（18.6 - 30.2%）在停用甲状腺素后s-Tg升高（至高于1 ng/ml）。
评估u-Tg水平可能是用于定义极佳反应的更好参数，因为u-Tg更稳定、方便、经济，且无甲状腺功能减退这一副作用。
