Rosario Pedro Weslley, Mourão Gabriela Franco, dos Santos Juan Bernard Nascimento, Calsolari Maria Regina
1 Postgraduate Program, Santa Casa de Belo Horizonte , Belo Horizonte, Brazil .
Thyroid. 2014 Mar;24(3):533-6. doi: 10.1089/thy.2013.0427. Epub 2013 Dec 10.
At present, empirical radioactive iodine therapy is recommended for patients with thyroid cancer and elevated thyroglobulin (Tg) after initial therapy when neck ultrasonography (US), chest computed tomography (CT), and 18-fluorodeoxyglucose positron emission tomography (FDG-PET) do not reveal metastases. The objective of this study was to determine whether empirical (131)I therapy is indeed useful in these patients.
Patients with papillary thyroid cancer submitted to total thyroidectomy followed by remnant ablation with (131)I in whom whole-body scanning at the time of ablation (WBS-ablation) did not reveal metastases and who had elevated Tg after initial therapy were selected. Included in the study were patients with basal Tg >2 ng/mL or Tg >5 ng/mL after stimulation with recombinant human thyrotropin or Tg >10 ng/mL after levothyroxine withdrawal for 4 weeks. All patients were first investigated by neck US and chest CT. FDG-PET/CT was performed in patients with negative US and CT. The final sample of this study consisted of patients with negative US, CT, and FDG-PET/CT. These patients received an activity of 100 mCi (131)I and were submitted to posttherapy WBS (RxWBS).
Among the 24 patients receiving empirical (131)I therapy, no ectopic uptake was seen in 23 and mild uptake in the thyroid bed (<0.5%) in 15. Only one patient presented pulmonary metastases detected by RxWBS. Disease was observed in two other patients during short-term follow-up (mean 22 months), one with lymph node metastases diagnosed by a repeat US and one with bone metastases diagnosed by CT and FDG-PET scans.
We conclude that RxWBS rarely reveals disease in patients with elevated Tg after ablation, but with negative findings on WBS-ablation, US, CT, and FDG-PET. In this situation, empirical (131)I therapy should be restricted to patients with documented progression of serum Tg.
目前，对于甲状腺癌患者，在初次治疗后甲状腺球蛋白（Tg）升高且颈部超声（US）、胸部计算机断层扫描（CT）和18-氟脱氧葡萄糖正电子发射断层扫描（FDG-PET）未发现转移灶时，推荐进行经验性放射性碘治疗。本研究的目的是确定经验性¹³¹I治疗在这些患者中是否确实有用。
选取接受甲状腺全切除术并随后用¹³¹I进行残余甲状腺组织消融的乳头状甲状腺癌患者，这些患者在消融时的全身扫描（WBS-消融）未发现转移灶且初次治疗后Tg升高。纳入研究的患者包括基础Tg>2 ng/mL或重组人促甲状腺素刺激后Tg>5 ng/mL或左甲状腺素停药4周后Tg>10 ng/mL的患者。所有患者首先接受颈部US和胸部CT检查。US和CT检查结果为阴性的患者进行FDG-PET/CT检查。本研究的最终样本包括US、CT和FDG-PET/CT检查结果均为阴性的患者。这些患者接受100 mCi的¹³¹I治疗，并进行治疗后全身扫描（RxWBS）。
在接受经验性¹³¹I治疗的24例患者中，23例未发现异位摄取，15例甲状腺床有轻度摄取（<0.5%）。仅1例患者通过RxWBS发现肺转移。在短期随访（平均22个月）期间，另外2例患者发现疾病，1例经重复US诊断为淋巴结转移，1例经CT和FDG-PET扫描诊断为骨转移。
我们得出结论，RxWBS在消融后Tg升高但WBS-消融、US、CT和FDG-PET检查结果为阴性的患者中很少发现疾病。在这种情况下，经验性¹³¹I治疗应仅限于血清Tg有记录的进展患者。
