无创吸入式麻醉精准肺野照射装置在小鼠肺损伤研究中的应用

目的 探索小鼠放射性肺损伤模型中大批量、快速、低成本实现全肺野精准照射的有效方法，普及这一重要放射生物学模型在多领域的应用。方法 采用8~10周龄C57BL6雌性小鼠，使用micro-CT三维重建图像进行肺部解剖学参数测量并确定放射野范围（n=12）。结合标准化胸腔暴露及固定、无创通气麻醉等手段建立"一体化"麻醉、固定、定位装置，借助常规医用直线加速器完成批量小鼠精准肺野照射。结果 小鼠CT图像三维重建后在冠状位与矢狀位图像上确定肺结构的解剖位置与尺寸平均值。并进一步根据小鼠呼吸频率及幅度确定受呼吸频率影响的肺野上界、中线和下界，并将测量值标记于专门设计的肺野照射装置用来指导实际操作。本装置大致可分为小鼠固定架和麻醉通气系统两部分构成。固定架用以安置每排10只小鼠用弹力栓妥善固定暴露胸腔。照射中通过麻醉面罩全程给予异氟烷混合气体，确保实验过程中小鼠处于深度麻醉以及均匀呼吸动度。结论 本研究设计的集麻醉、固定、定位为一体的"弹匣式"小鼠肺野照射装置，可显著增加胸部放射实验的准确性、简易性、安全性、稳定性和高效性。大幅减低实验成本和对高端辐照设备的依赖，具有一定的实际应用及推广价值。

Application of non-invasive inhalation anesthesia precision thoracic irradiation device in a mouse model

Objective To develop a large scale, practical and cost-effective method for precision thoracic irradiation in a mouse model, and to popularize this important radiobiology model in many fields.Methods A total of 12 C57BL6 female mice (8~10 weeks old) were used for quantitative assessment of pulmonary anatomical parameters and radioactivity range by using three-dimensional reconstruction of micro-CT images. Integrating non-invasive inhalation anesthesia standardized thoracic cavity exposure and multiple fixation technology, a specially designed mice holder was established to facilitating whole thoracic irradiation (WTI) by a clinical Linac system.Results The parameters of lung and neighbor structures were measured in coronal and sagittal views of reconstructed CT images. Taking the breath motion into account, the determined anatomical parameters were utilized to defining the accurate irradiation field and being labeled on the specially designed device for positioning purposes. This device can be roughly divided into two parts:a mouse fixation frame and an anesthesia ventilation system. The fixation component was available for 10 mice to be properly fixed with elastic bolt at the same time. An isoflurane mixed gas was administered through the anesthesia mask to ensure that the mice were deeply anesthetized and stable throughout the irradiation course.Conclusion The present mice WTI cassette is incorporated with multiple functions such as inhalation anesthesia, immobilization and accurately positioning, which can significantly increase the accuracy, simplicity, safety, stability, and high efficiency of thoracic irradiation experiments.. It reduces remarkably the experimental cost and less depends on the expensive small animal IGRT system. This device is therefore of practical significance in the field.