Department of Small Animal Clinical Sciences, Western College of Veterinary Medicine, Saskatoon, Saskatchewan, Canada.
J Vet Intern Med. 2021 Nov;35(6):2646-2651. doi: 10.1111/jvim.16261. Epub 2021 Sep 13.
Historical and recent literature disagree on whether a higher PO I dosage, compared to IV or SC routes, is required for successful resolution of spontaneous hyperthyroidism in cats, necessitating investigation into the effect of PO and injectable radioactive iodine administration on % thyroidal radioactive iodine uptake (RAIU).
HYPOTHESIS/OBJECTIVES: To investigate the effect of PO and SC routes of I administration on paired % thyroidal RAIU in euthyroid cats. Specifically, a 1.5-fold difference (50% relative change) was hypothesized, which in absolute terms can be expressed as a 3.25% increase in the mean %RAIU of 7.04% after PO I administration to 10.56% after SC dosing.
Seven healthy euthyroid teaching-research colony cats.
A randomized, radiologist-blinded crossover study comparing %RAIU after PO and SC I administration.
Percentage thyroidal RAIU values (mean ± SD; 95% confidence interval) after PO (4.81% ± 1.63%; 3.30%-6.23%) and SC (5.26% ± 2.43%; 3.01%-7.51%) I administration were associated with a median within-pair absolute difference of 0.2% (range: min, 0.1%-max, 4.9%). Statistical significance was not achieved (P = .45). Six of 7 cats had a within-pair absolute difference of 0.1% to 0.9% (relative change of 4%-20%), but a single outlier cat had a within-pair absolute difference of 4.9% (relative change of 108%).
This study did not detect an effect of I administration route on paired % thyroidal RAIU in euthyroid cats. However, a type 2 statistical error due to small sample size is possible.
历史和近期文献对于猫自发性甲状腺功能亢进症的治疗，即通过口服（PO）或静脉（IV）或皮下（SC）途径给予更高剂量的碘 131（PO 相较于 IV 或 SC 途径）是否更有效存在争议，这需要研究 PO 和注射用放射性碘对甲状腺放射性碘摄取率（RAIU）的影响。
假设/目的：研究 PO 和 SC 途径给予碘 131 对甲状腺功能正常的猫配对甲状腺 RAIU 的影响。具体而言，假设 PO 途径给药后甲状腺 RAIU 增加 50%（相对变化），绝对值表示 PO 给药后甲状腺 RAIU 从 7.04%增加至 10.56%，增加 3.25%。
7 只健康的教学研究用猫。
一项比较 PO 和 SC 途径给予碘 131 后甲状腺 RAIU 的随机、放射科医师设盲交叉研究。
PO（4.81%±1.63%；3.30%-6.23%）和 SC（5.26%±2.43%；3.01%-7.51%）碘 131 给药后，甲状腺 RAIU 值的中位数（均数±标准差；95%置信区间）呈配对关系，绝对差值的中位数为 0.2%（范围：最小值，0.1%-最大值，4.9%）。未达到统计学意义（P = .45）。7 只猫中有 6 只的配对绝对差值为 0.1%至 0.9%（相对变化 4%-20%），但有 1 只离群值猫的配对绝对差值为 4.9%（相对变化 108%）。
本研究未发现甲状腺功能正常的猫中碘 131 给药途径对配对甲状腺 RAIU 的影响。然而，由于样本量小，可能存在 II 型统计误差。
