Rosário Pedro Weslley S do, Vasconcelos Flavio P J, Cardoso Ludmilla D, Lauria Márcio W, Rezende Leonardo L, Padrão Eduardo L, Barroso Alvaro L, Guimarães Valéria C, Purisch Saulo
Department of Thyroid, Santa Casa de Belo Horizonte, MG.
Arq Bras Endocrinol Metabol. 2006 Feb;50(1):91-6. doi: 10.1590/s0004-27302006000100013. Epub 2006 Apr 17.
Thyroxine (T4) withdrawal or recombinant TSH is used for the stimulation of thyroglobulin (Tg), whole-body scanning (WBS) and iodine-131 treatment in patients with thyroid carcinoma. This study evaluated the T4 dose reduction protocol as an alternative for patients' preparation. Fifty-one patients were submitted to total T4 withdrawal for WBS and Tg measurement. T4 treatment was then resumed and maintained until TSH reached levels < 0.3 mIU/l. The T4 dose was then decreased to 0.8 microg/kg/day and TSH was measured weekly. Tg was assayed when TSH was > 30 mIU/l. Patients diagnosed with the disease upon initial evaluation were treated. We also evaluated the clinical and laboratory changes observed for both preparations. Using the reduced dose protocol, TSH levels > 30 mIU/l were reached within 6 and 8 weeks in 84.6 and 100% of the patients, respectively. T4 withdrawal was associated with more common symptoms of hypothyroidism and elevation of creatine kinase (CK) and LDL cholesterol. The T4 dose reduction protocol proved to be useful for Tg stimulation and ablative therapy, without the complication of severe hypothyroidism or the cost of recombinant TSH.
甲状腺素（T4）撤药或重组促甲状腺激素（TSH）用于刺激甲状腺球蛋白（Tg）、进行全身扫描（WBS）以及对甲状腺癌患者进行碘-131治疗。本研究评估了T4剂量减少方案作为患者准备的一种替代方法。51例患者接受了T4完全撤药以进行WBS和Tg测量。然后恢复T4治疗并维持，直至TSH水平降至<0.3 mIU/l。随后将T4剂量降至0.8 μg/kg/天，并每周测量TSH。当TSH>30 mIU/l时检测Tg。对初始评估时诊断为该病的患者进行治疗。我们还评估了两种准备方法所观察到的临床和实验室变化。采用减量方案时，分别有84.6%和100%的患者在6周和8周内TSH水平>30 mIU/l。T4撤药与更常见的甲状腺功能减退症状以及肌酸激酶（CK）和低密度脂蛋白胆固醇升高有关。T4剂量减少方案被证明对Tg刺激和消融治疗有用，且无严重甲状腺功能减退的并发症或重组TSH的费用。
