Small Animal Internal Medicine Division, Department of Clinical Veterinary Medicine, Vetsuisse Faculty University of Bern, Bern, Switzerland.
These authors contributed equally to this work.
Open Vet J. 2022 Mar-Apr;12(2):231-241. doi: 10.5455/OVJ.2022.v12.i2.11. Epub 2022 Apr 5.
Hyperthyroidism is the most frequent endocrinopathy in older cats. To date, there is no consensus on how to best calculate the dose of radioiodine to administer to hyperthyroid cats.
The goals of this study were to compare thyroid function, renal function, and survival time between hyperthyroid cats receiving a fixed dose of radioiodine and those receiving an individualized dose calculated using a clinical scoring system.
Medical records of 110 cats treated with radioiodine therapy at the University of Bern between 2010 and 2020 were reviewed. Thyroid function, renal function, and survival of cats treated with a fixed dose of radioiodine (2010-2015; = 50) were compared to those of cats treated with an individualized dose (2015-2020; = 60) at different time points after therapy.
Treatment with a fixed dose of radioiodine (mean = 168 ± 26 MBq) was associated with 69% of euthyroidism, 19% persistent hyperthyroidism, and 12% hypothyroidism, whereas treatment with an individualized dose (mean = 120 ± 30 MBq) led to 54% euthyroidism, 23% hyperthyroidism, and 23% hypothyroidism ( = 0.73). More than 12 months after treatment, the incidence of azotemia was comparable between cats treated with a fixed dose (37%) and those treated with an individualized dose (31%) ( = 0.77). No factors were found to be predictive of treatment failure (hypothyroidism or hyperthyroidism) after therapy. Median survival time after radioiodine therapy was 44 months. In a multivariate analysis, persistent hyperthyroidism was the only variable independently associated with a shorter survival time (HR = 6.24, = 0.002).
The method of calculating the dose of radioiodine (fixed . individualized) to treat feline hyperthyroidism does not appear to be decisive for posttreatment thyroid function, renal function, or survival.
甲状腺功能亢进是老年猫最常见的内分泌疾病。迄今为止，对于如何最佳计算放射性碘治疗甲状腺功能亢进猫的剂量，尚无共识。
本研究的目的是比较接受固定剂量放射性碘治疗和接受基于临床评分系统计算的个体化剂量治疗的甲状腺功能亢进猫的甲状腺功能、肾功能和生存时间。
回顾了 2010 年至 2020 年在伯尔尼大学接受放射性碘治疗的 110 只猫的病历。比较了接受固定剂量放射性碘（2010-2015 年； = 50）治疗的猫和接受个体化剂量（2015-2020 年； = 60）治疗的猫在治疗后不同时间点的甲状腺功能、肾功能和生存情况。
接受固定剂量放射性碘（平均剂量=168 ± 26 MBq）治疗的猫，69%达到甲状腺功能正常，19%持续甲状腺功能亢进，12%甲状腺功能减退，而接受个体化剂量（平均剂量=120 ± 30 MBq）治疗的猫，54%达到甲状腺功能正常，23%甲状腺功能亢进，23%甲状腺功能减退（ = 0.73）。治疗后 12 个月以上，接受固定剂量治疗的猫（37%）和接受个体化剂量治疗的猫（31%）发生氮质血症的发生率无差异（ = 0.77）。未发现任何因素可预测治疗后（甲状腺功能减退或甲状腺功能亢进）治疗失败。接受放射性碘治疗后的中位生存时间为 44 个月。多变量分析显示，持续甲状腺功能亢进是唯一与较短生存时间相关的独立变量（HR=6.24， = 0.002）。
计算放射性碘（固定剂量-个体化剂量）治疗猫甲状腺功能亢进剂量的方法似乎对治疗后甲状腺功能、肾功能或生存时间没有决定性影响。
