可疑甲状腺球蛋白增高性分化型甲状腺癌患者经131I治疗后的临床转归

背景与目的： 分化型甲状腺癌（differentiated thyroid cancer,DTC）中可疑甲状腺球蛋白（thyroglobulin,Tg）水平增高但无明确结构性病灶者预后差异大,临床治疗决策存在较大争议,本研究拟探究¹³¹I治疗及不同治疗剂量对于这类患者临床转归的影响。方法： 回顾并分析2007—2021年就诊于北京协和医院核医学科的138例DTC全切术后可疑Tg水平增高的患者,依据首次¹³¹I治疗剂量分为低（剂量为1.11 GBq）、中（1.11 GBq<剂量≤3.70 GBq）、高（3.70 GBq<剂量≤7.40 GBq）3组,观察不同剂量¹³¹I治疗后6个月的短期及后续未再行其他干预患者的长期疗效,并进一步观察经初始治疗评估为生化疗效不佳（biochemical incomplete response,BIR）患者的临床转归。采用受试者工作特征（receiver operating characteristic,ROC）曲线评估预测结构性疗效不佳（structural incomplete response,SIR）和远处转移的刺激性Tg（stimulated Tg,sTg）的最佳界值点。结果： 低、中、高3个剂量组中分别有6.7%、13.5%、7.0%的患者短期疗效达到疗效满意（excellent response,ER）,3组间总体疗效差异无统计学意义（H=1.02,P=0.60）。常规随访下3组患者的长期疗效同样差异无统计学意义（H=2.94,P=0.23）。经初始治疗评估为BIR的患者经常规随访和再次¹³¹I治疗后的临床转归差异无统计学意义（U=324.5,P=0.15）。预测SIR和远处转移的sTg最佳界值点分别为27.5和61.7 ng/mL。结论： 可疑Tg水平增高的DTC患者复发率较高,以27.5 ng/mL为sTg界值点有助于尽早识别这部分患者。¹³¹I治疗有助于术后可疑Tg水平增高患者快速达到ER,但高剂量¹³¹I治疗未对患者的预后产生增益效应;再次¹³¹I治疗对于BIR患者未显示出进一步获益。

Clinical outcome of 131I therapy in differentiated thyroid cancer patients with suspicious high thyroglobulin concentration

Background and purpose: The prognosis of differentiated thyroid cancer (DTC) patients with suspicious high thyroglobulin (Tg) concentration and without explicit structural lesions varies from each other, hence the clinical treatment decisions including ¹³¹I therapy remain controversial. This study aimed to explore the effects of ¹³¹I treatment and the therapeutic dose on the clinical outcome of these patients. Methods: The study included 138 DTC patients treated in Department of Nuclear Medicine, Peking Union Medical College Hospital from 2007 to 2021, who had undergone total thyroidectomy and subsequent ¹³¹I therapy. All patients were divided into 3 groups as low dose (dose=1.11 GBq), medium dose (1.11 GBq131I therapy. We compared the short-term and end-of period response to therapy among these three groups, and further observed the clinical outcome of patients with biochemical incomplete response (BIR) after initial treatment. The receiver operating characteristic (ROC) curve was employed to evaluate the predictive value of stimulated Tg (sTg) levels in patients with structural incomplete response (SIR) and distant metastasis. Results: For the short-term response, the rate of excellent response (ER) was 6.7%, 13.5% and 7.0% in low, medium and high dose group, respectively. The short-term response showed no statistically significant difference among three groups (H=1.02, P=0.60). The end-of-period response among the three groups under routine follow-up also showed no significant difference (H=2.94, P=0.23). No significant difference was observed in the clinical outcome of patients with BIR after routine follow-up and second ¹³¹I treatment (U=324.5, P=0.15). The diagnostic critical point (DCP) of sTg to predict SIR and distant metastasis was 27.5 and 61.7 ng/mL, respectively. Conclusion: DTC patients with suspicious high Tg concentration has high recurrence risk, taking 27.5 ng/mL as the cut-off of sTg is helpful to identify the patients with high recurrence risk early. ¹³¹I treatment is helpful for these patients to achieve ER as soon as possible. However, high-dose ¹³¹I did not have greater benefits on the prognosis of these patients. Second ¹³¹I treatment showed no further benefit for BIR patients.