Feline Hyperthyroid Clinic, Anderson Moores Veterinary Specialists, Winchester, SO21 2LL, UK.
Radiation Protection, University Hospital Southampton, Southampton, SO16 6YD, UK.
J Small Anim Pract. 2022 Oct;63(10):763-768. doi: 10.1111/jsap.13533. Epub 2022 Aug 1.
Felinehyperthyroidism is the most common endocrine disease of older cats and radioiodine is considered to be the gold standard treatment. Isolation periods following treatment vary depending on both individual treatment facilities and the relevant legislation of the country; therefore, there is no recognised standardised protocol defining the length of isolation. This work describes how our institution validated that its owner restrictions met dose constraints by using a model of iodine retention to calculate the required duration and nature of owner restrictions.
The retained radioactivity of cats at the point of discharge was used to simulate the radiation dose to owners in the 90 days following release. The model created was used to calculate the minimum duration of isolation for a range of administered activities and owner restrictions.
Using the model, it was found that when injected with the maximum dose used, 222 MBq radioiodine, it was possible to release cats after 14 days of isolation and keep owner doses below 0.30 mSv (whole-body effective dose constraint for a single radiation source) with some restrictions. It was possible to release after 23 days with no restrictions.
The present study provides clinicians with a consistent and verified method in which they can calculate the isolation periods for radioiodine-treated cats.
猫甲状腺功能亢进是老年猫最常见的内分泌疾病，放射性碘被认为是黄金标准治疗方法。治疗后的隔离期因个体治疗设施和国家相关法规而异；因此，没有公认的标准化协议来定义隔离期的长度。本研究描述了我们的机构如何使用碘保留模型来计算所需的隔离持续时间和性质，以验证其主人限制符合剂量限制。
使用出院时猫的放射性保留量来模拟释放后 90 天内主人的辐射剂量。使用创建的模型来计算一系列放射性碘活度和主人限制下的最小隔离时间。
使用该模型，当注射最大剂量 222MBq 放射性碘时，在隔离 14 天后可以释放猫，并且在有一些限制的情况下将主人剂量保持在 0.30mSv 以下（单一辐射源的全身有效剂量限制）。在没有限制的情况下，23 天后可以释放。
本研究为临床医生提供了一种一致且经过验证的方法，可计算放射性碘治疗猫的隔离期。
