L-T3 全身闪烁显像准备：一项随机对照试验。

L-T3 preparation for whole-body scintigraphy: a randomized-controlled trial.

机构信息

Department of Medicine, Division of Endocrinology, Faculté de Médécine et des sciences de santé, Université de Sherbrooke, Sherbrooke, Québec, Canada.

出版信息

Clin Endocrinol (Oxf). 2007 Dec;67(6):839-44. doi: 10.1111/j.1365-2265.2007.02972.x. Epub 2007 Jul 20.

DOI:10.1111/j.1365-2265.2007.02972.x

PMID:17645577

Abstract

BACKGROUND

Patients with thyroid cancer often need whole-body scintigraphy (WBS) under TSH stimulation after 4-6 weeks withdrawal from levothyroxine (L-T(4)). Patients often become severely hypothyroid with impaired quality of life. Liothyronine (L-T(3)) substitution is used empirically to prepare patients; however, no data exist to prove its benefit. Objectives To compare the hypothyroid state in patients receiving either placebo or L-T(3) following L-T(4) withdrawal and to evaluate the time needed for adequate TSH elevation in preparation for WBS.

METHODS

At the time of L-T(4) withdrawal, patients were randomized to receive L-T(3 )(50 microg qd) or placebo for 3 weeks, after which treatment was stopped. A validated evaluation of hypothyroidism (Billewicz score) was administered in a double-blind fashion every 2 weeks until the WBS. TSH, fT(4) and fT(3) were measured weekly.

RESULTS

A total of 20 patients were randomized between September 2003 and May 2005. There was no difference in the Billewicz score at any time between the two groups. Before WBS, both groups were profoundly hypothyroid. TSH at time of WBS was similar in both groups. The time needed to reach a TSH level of more than 30 mUI/l was longer in L-T(3) group (mean +/- SD: 32 +/- 4 days vs. 17 +/- 9 days in placebo group, P = 0.006).

CONCLUSION

Preparation for WBS with L-T(3) does not prevent profound hypothyroidism and delays TSH elevation required for WBS. L-T(4) withdrawal alone for 2-3 weeks is simpler and sufficient to allow TSH to reach a level of more than 30 mUI/l in the majority of patients without increasing morbidity from hypothyroidism.

摘要

背景

甲状腺癌患者在停用左甲状腺素（L-T4）4-6 周后，通常需要进行 TSH 刺激下的全身闪烁扫描（WBS）。此时患者往往会出现严重的甲状腺功能减退，生活质量受损。因此，临床上常采用甲状腺素（L-T3）替代治疗来进行准备，但尚无证据表明其有益。本研究旨在比较 L-T4 停药后患者接受 L-T3 或安慰剂治疗时的甲状腺功能减退状态，并评估为 WBS 准备而使 TSH 升高至适当水平所需的时间。

方法

在停用 L-T4 时，患者被随机分为 L-T3（50μg qd）组或安慰剂组，持续 3 周，然后停药。在双盲条件下，每 2 周使用经过验证的甲状腺功能减退评估（Billewicz 评分）进行评估，直至 WBS。每周检测 TSH、游离甲状腺素（fT4）和游离三碘甲状腺原氨酸（fT3）。

结果

2003 年 9 月至 2005 年 5 月期间共纳入 20 名患者。两组在任何时间的 Billewicz 评分均无差异。在 WBS 前，两组均为严重甲状腺功能减退。两组 WBS 时的 TSH 相似。L-T3 组达到 TSH 水平＞30mUI/L 所需的时间更长（平均±SD：32±4 天 vs. 安慰剂组 17±9 天，P=0.006）。