Ma Chao, Xie Jiawei, Kuang Anren
Department of Nuclear Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China.
J Nucl Med. 2005 Jul;46(7):1164-70.
The long-term monitoring of patients with differentiated thyroid carcinoma (DTC) is essential throughout the patient's life after total or nearly total thyroidectomy followed by 131I remnant ablation and thyroid hormone suppression of thyroid-stimulating hormone (TSH). Sensitive surveillance for DTC recurrences and metastases includes radioiodine diagnostic whole-body scanning (DWBS) and measurement of serum thyroglobulin (Tg) levels after endogenous or exogenous TSH stimulation. Serum Tg levels during thyroid hormone withdrawal usually are correlated well with the results of DWBS. In general, Tg levels undetectable by DWBS suggest complete remission, whereas detectable or elevated Tg concentrations are suggestive of the presence of 131I uptake in local or distant metastases. However, DTC patients with a positive Tg test and negative 131I DWBS results (Tg+ DWBS-) have been observed in follow-up studies. The management of these cases begets controversy.
We electronically searched Medline (1966-2004.3), Embase (1984-2003), the Cochrane Library (2004, 2nd edition), CNKI (1994-2004), and CBM-DISC (1978-2004). We also manually searched the Chinese Journal of Isotopes, Radiologia pratica, and the Chinese Journal of Endocrinology and Metabolism.
Ten serial observations and 3 nonrandomized controlled trials were found. The available data showed that of 314 patients who were treated empirically with 131I, 194 (62%) of 314 displayed pathologic uptake in the thyroid bed, lung, bone, mediastinum, and lymph nodes. In studies with Tg-on and Tg-off data, 171 (63%) of 271 patients achieved a decrease in Tg.
On the basis of data from recent studies, 131I therapy should be individualized according to clinical characteristics. More significantly, a decrease in Tg levels was achieved in 63% of DTC patients with Tg+ DWBS-, suggesting that 131I therapy does have a therapeutic effect when the Tg level is considered an index of tumor burden. The 62% positive posttherapy whole-body scanning results also indicated that a therapeutic dose of 131I could reveal approximately one half of previously undiagnosed lesions in some patients. Therefore, 131I therapy may be justified in patients with Tg levels of > 10 microg/L and DWBS- and who are at high risk of any recurrence.
分化型甲状腺癌（DTC）患者在全甲状腺切除或近全甲状腺切除、131I残余甲状腺组织消融及甲状腺激素抑制促甲状腺激素（TSH）后，终生进行长期监测至关重要。对DTC复发和转移的敏感监测包括放射性碘诊断性全身扫描（DWBS）以及内源性或外源性TSH刺激后血清甲状腺球蛋白（Tg）水平的测定。甲状腺激素撤药期间的血清Tg水平通常与DWBS结果密切相关。一般来说，DWBS未检测到Tg水平提示完全缓解，而可检测到或升高的Tg浓度提示局部或远处转移灶存在131I摄取。然而，在随访研究中观察到了Tg检测结果为阳性而131I DWBS结果为阴性（Tg+ DWBS-）的DTC患者。这些病例的处理引发了争议。
我们通过电子检索了Medline（1966 - 2004.3）、Embase（1984 - 2003）、Cochrane图书馆（2004年，第2版）、中国知网（1994 - 2004）和中国生物医学文献数据库（1978 - 2004）。我们还手动检索了《中华核医学杂志》、《实用放射学杂志》以及《中华内分泌代谢杂志》。
共找到10项系列观察研究和3项非随机对照试验。现有数据显示，314例接受131I经验性治疗的患者中，314例中的194例（62%）在甲状腺床、肺、骨、纵隔和淋巴结出现病理性摄取。在有Tg开启和Tg关闭数据的研究中，271例患者中的171例（63%）Tg水平下降。
根据近期研究数据，131I治疗应根据临床特征个体化。更重要的是，63%的Tg+ DWBS-的DTC患者Tg水平下降，这表明当将Tg水平视为肿瘤负荷指标时，131I治疗确实具有治疗效果。治疗后全身扫描62%的阳性结果还表明，治疗剂量的131I在一些患者中可发现约一半先前未诊断出的病灶。因此，对于Tg水平>10μg/L、DWBS-且有任何复发高风险的患者，131I治疗可能是合理的。
