Ito Shinji, Iwano Shingo, Kato Katsuhiko, Naganawa Shinji
Department of Radiology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, 466-8550, Japan.
Department of Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, 1-1-20 Daiko-Minami, Higashi-ku, Nagoya, 461-8673, Japan.
Ann Nucl Med. 2018 Jul;32(6):418-424. doi: 10.1007/s12149-018-1261-0. Epub 2018 May 15.
To identify prognostic factors associated with a low-iodine diet (LID) and the amount of remnant thyroid tissue in Japanese patients with differentiated thyroid cancer (DTC) who received initial I-131 remnant ablation (RAI) using a fixed low dose of I-131 (1110 MBq).
In this prospective study, we enrolled 45 patients. Patients were classified into a self-managed LID group and a strict LID group. We measured the urinary iodine concentration on the day of RAI after patients consumed LID for 2 weeks. Thyroid-stimulating hormone-induced thyroglobulin (Tg) levels and I-131 uptake by the remnant thyroid tissue were also evaluated. A response-evaluation whole-body scan (WBS) was performed 6-8 months after RAI to determine the outcome of the therapy.
Post-LID urinary iodine levels of the strict LID group tended to be lower than those of the self-managed LID group. Twenty-five cases (56%) showed absence of uptake, whereas 20 cases (44%) showed residual uptake on the response-evaluation WBS. There were no significant differences between "absence" and "residual" groups in urinary iodine concentrations and Tg levels (p = 0.253 and p = 0.234, respectively). However, significant differences were observed in I-131 uptake by the thyroid bed (p = 0.035).
For patients following the current Japanese method of a 2-week LID, the urinary iodine concentration was not a predictive factor for the successful outcome of RAI. In contrast, low I-131 uptake by the thyroid bed, revealed by the scintigram after RAI, may serve as a favorable predictive factor.
确定在接受固定低剂量碘-131（1110MBq）进行首次碘-131残余甲状腺组织消融（RAI）的日本分化型甲状腺癌（DTC）患者中，与低碘饮食（LID）及残余甲状腺组织量相关的预后因素。
在这项前瞻性研究中，我们纳入了45例患者。患者被分为自我管理的低碘饮食组和严格低碘饮食组。在患者进行2周低碘饮食后，于RAI当天测量尿碘浓度。还评估了促甲状腺激素诱导的甲状腺球蛋白（Tg）水平以及残余甲状腺组织对碘-131的摄取情况。在RAI后6 - 8个月进行反应评估全身扫描（WBS）以确定治疗效果。
严格低碘饮食组的低碘饮食后尿碘水平往往低于自我管理的低碘饮食组。在反应评估WBS上，25例（56%）显示无摄取，而20例（44%）显示有残余摄取。“无摄取”组和“残余摄取”组在尿碘浓度和Tg水平上无显著差异（p分别为0.253和0.234）。然而，甲状腺床对碘-131的摄取存在显著差异（p = 0.035）。
对于采用当前日本2周低碘饮食方法的患者，尿碘浓度并非RAI成功结局的预测因素。相比之下，RAI后闪烁扫描显示的甲状腺床低碘-131摄取可能是一个有利的预测因素。
