Tin-117m (117mSn) is used to treated dogs with osteoarthritic joints by radiosynoviorthesis. The internal conversion and Auger electrons emitted by the 117mSn provide the therapeutic effect. Sn-117m also emits gamma rays, of which the most significant is 158.6 keV. The external radiation field around a treated dog is of interest to limit the dose to the owners/caretakers of the dog. The dog's torso attenuates the radiation being emitted toward the opposite side of the dog's body. This leads to a radiation field that is significantly non-isotropic. This study characterizes the anisotropy of this field to permit maximum dose rate measurements to be used to calculate the dose to individuals in the vicinity of the dog. Measurements were made in nine directions and at two distances, 0.3 and 1.0 m, to characterize common distances and spatial orientations for human-dog interactions. From these measurements, the percent reduction in the average dose rate compared to the maximum dose rate was determined. From a radiation safety perspective, the important factor is the minimum amount of shielding effectiveness or percent reduction that can be expected. A reasonable measure for this value is the fifth percentile of the shielding effectiveness distribution. The fifth percentile shielding effectiveness measures are 27% and 21% at 0.3 and 1.0 m, respectively.

中文翻译：

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犬 Sn-117m 治疗后辐射场的各向异性。

Tin-117m (117mSn) 用于通过放射滑膜疗法治疗患有骨关节炎的狗。117mSn 的内部转换和发射的俄歇电子提供了治疗效果。Sn-117m也发射伽马射线，其中最重要的是158.6 keV。受治疗的狗周围的外部辐射场有利于限制狗的主人/看护者的剂量。狗的躯干减弱了向狗身体另一侧发射的辐射。这导致辐射场明显非各向同性。这项研究描述了该场的各向异性，以允许使用最大剂量率测量来计算狗附近个体的剂量。在九个方向和两个距离（0.3 和 1.0 m）进行测量，以表征人与狗交互的常见距离和空间方向。通过这些测量，可以确定平均剂量率相对于最大剂量率的降低百分比。从辐射安全的角度来看，重要的因素是可预期的最小屏蔽效能或降低百分比。该值的合理衡量标准是屏蔽效能分布的第五个百分位数。第五个百分位屏蔽效能测量值在 0.3 和 1.0 m 处分别为 27% 和 21%。