技术说明：使用3D打印固定装置对小鼠脑照射靶向准确性进行免疫组织化学评估

Technical Note: Immunohistochemical evaluation of mouse brain irradiation targeting accuracy with 3D-printed immobilization device.

作者信息

Zarghami Niloufar, Jensen Michael D, Talluri Srikanth, Foster Paula J, Chambers Ann F, Dick Frederick A, Wong Eugene

机构信息

Department of Medical Biophysics, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 3K7, Canada.

Department of Biochemistry, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 3K7, Canada and London Regional Cancer Program, London Health Sciences Centre, 800 Commissioners Road East, London, Ontario N6A 5W9, Canada.

出版信息

Med Phys. 2015 Nov;42(11):6507-13. doi: 10.1118/1.4933200.

DOI:10.1118/1.4933200

PMID:26520740

Abstract

PURPOSE

Small animal immobilization devices facilitate positioning of animals for reproducible imaging and accurate focal radiation therapy. In this study, the authors demonstrate the use of three-dimensional (3D) printing technology to fabricate a custom-designed mouse head restraint. The authors evaluate the accuracy of this device for the purpose of mouse brain irradiation.

METHODS

A mouse head holder was designed for a microCT couch using cad software and printed in an acrylic based material. Ten mice received half-brain radiation while positioned in the 3D-printed head holder. Animal placement was achieved using on-board image guidance and computerized asymmetric collimators. To evaluate the precision of beam localization for half-brain irradiation, mice were sacrificed approximately 30 min after treatment and brain sections were stained for γ-H2AX, a marker for DNA breaks. The distance and angle of the γ-H2AX radiation beam border to longitudinal fissure were measured on histological samples. Animals were monitored for any possible trauma from the device.

RESULTS

Visualization of the radiation beam on ex vivo brain sections with γ-H2AX immunohistochemical staining showed a sharp radiation field within the tissue. Measurements showed a mean irradiation targeting error of 0.14±0.09 mm (standard deviation). Rotation between the beam axis and mouse head was 1.2°±1.0° (standard deviation). The immobilization device was easily adjusted to accommodate different sizes of mice. No signs of trauma to the mice were observed from the use of tooth block and ear bars.

CONCLUSIONS

The authors designed and built a novel 3D-printed mouse head holder with many desired features for accurate and reproducible radiation targeting. The 3D printing technology was found to be practical and economical for producing a small animal imaging and radiation restraint device and allows for customization for study specific needs.

摘要

目的

小动物固定装置有助于将动物放置在可重复成像和精确聚焦放射治疗的位置。在本研究中，作者展示了使用三维（3D）打印技术制造定制设计的小鼠头部固定器。作者评估了该装置用于小鼠脑部照射的准确性。

方法

使用计算机辅助设计软件为微型计算机断层扫描（microCT）床设计了一个小鼠头部固定器，并使用丙烯酸基材料进行打印。十只小鼠在3D打印的头部固定器中接受半脑放射治疗。使用机载图像引导和计算机化非对称准直器实现动物放置。为了评估半脑照射时束定位的精度，在治疗后约30分钟处死小鼠，并对脑切片进行γ-H2AX染色，γ-H2AX是DNA断裂的标志物。在组织学样本上测量γ-H2AX放射束边界与大脑纵裂的距离和角度。监测动物是否受到该装置可能造成的任何创伤。