Postgraduate Program, Santa Casa de Belo Horizonte, Minas Gerais, Brazil.
Thyroid. 2013 May;23(5):617-9. doi: 10.1089/thy.2012.0050. Epub 2013 Apr 18.
One of the adverse effects of radioactive iodine (¹³¹I) treatment in patients with thyroid cancer is damage to the salivary and lacrimal glands. In almost all studies evaluating salivary and lacrimal gland dysfunction, the patients received ¹³¹I after levothyroxine (L-T4) withdrawal. Since the biokinetics of ¹³¹I after recombinant human thyrotropin (rhTSH) is not the same as in hypothyroidism, studies need to evaluate ¹³¹I-induced salivary and lacrimal toxicity after preparation with rhTSH. This prospective study investigated the occurrence of salivary and lacrimal damage after ablation with ¹³¹I using this preparation.
One hundred forty-eight patients who had a total thyroidectomy were included in the study. The subjects were evaluated after thyroidectomy during L-T4 use to exclude those who already showed symptoms or had a history of ocular or oral disease. Symptoms were investigated 12 and 18 months after ablation. In patients who had persistent symptoms, specific tests were performed to confirm glandular dysfunction and to rule out other causes.
Twelve months after ablation, symptoms of salivary or lacrimal dysfunction were observed in 10 (6.7%) patients, including oral symptoms in 8 (5.4%) and ocular symptoms in 6 (4%). Eighteen months after ¹³¹I, symptoms persisted in eight (5.4%) patients, including oral symptoms in seven (4.7%) and ocular symptoms in five (3.4%). In all of the patients, glandular dysfunction was confirmed by specific tests and other causes were ruled out. No symptoms were seen in the patients who received a low ¹³¹I dose (30 mCi). In the patients who received high ¹³¹I doses (100 or 150 mCi), symptoms were noted 12 months after ¹³¹I in 10 patients (9.2%), and 18 months after ¹³¹I in 8 patients (7.4%).
Apparently, the rates of salivary and lacrimal damage were lower than those reported in prospective studies that used similar ¹³¹I activities, but these studies were performed in patients who were hypothyroid at the time of ¹³¹I ablation. Further studies are needed to compare radiotoxicity between patients prepared for ¹³¹I ablation with rhTSH and those prepared for ¹³¹I ablation with L-T4 withdrawal.
放射性碘（¹³¹I）治疗甲状腺癌患者的不良反应之一是唾液腺和泪腺损伤。在评估唾液腺和泪腺功能障碍的几乎所有研究中，¹³¹I 治疗均在左甲状腺素（L-T4）停药后进行。由于重组人促甲状腺激素（rhTSH）后¹³¹I 的生物动力学与甲状腺功能减退症不同，因此需要研究使用 rhTSH 准备后¹³¹I 引起的唾液腺和泪腺毒性。这项前瞻性研究调查了使用这种准备方法进行¹³¹I 消融后唾液腺和泪腺损伤的发生情况。
本研究纳入了 148 例甲状腺全切除术患者。在使用 L-T4 进行甲状腺切除术期间评估患者，以排除那些已经出现症状或有眼部或口腔疾病病史的患者。消融后 12 个月和 18 个月时进行症状评估。在持续性症状的患者中，进行了特定的检查以确认腺体功能障碍并排除其他原因。
消融后 12 个月，有 10 例（6.7%）患者出现唾液或泪液功能障碍的症状，包括 8 例（5.4%）口腔症状和 6 例（4%）眼部症状。消融后 18 个月，8 例（5.4%）患者的症状持续存在，包括 7 例（4.7%）口腔症状和 5 例（3.4%）眼部症状。所有患者均通过特定检查证实腺体功能障碍，并排除其他原因。接受低¹³¹I 剂量（30 mCi）的患者未出现症状。在接受高¹³¹I 剂量（100 或 150 mCi）的患者中，¹³¹I 治疗后 12 个月有 10 例（9.2%）患者出现症状，¹³¹I 治疗后 18 个月有 8 例（7.4%）患者出现症状。
显然，唾液腺和泪腺损伤的发生率低于使用类似¹³¹I 活性的前瞻性研究报告的发生率，但这些研究是在¹³¹I 消融时甲状腺功能减退的患者中进行的。需要进一步的研究来比较 rhTSH 准备与 L-T4 停药准备进行¹³¹I 消融的患者之间的放射毒性。
