使用改良型工业微型计算机断层扫描进行图像引导放射治疗在临床前应用中的研究
Image-Guided Radiotherapy Using a Modified Industrial Micro-CT for Preclinical Applications.
作者信息
Felix Manuela C, Fleckenstein Jens, Kirschner Stefanie, Hartmann Linda, Wenz Frederik, Brockmann Marc A, Glatting Gerhard, Giordano Frank A
机构信息
Medical Radiation Physics/Radiation Protection, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany; Department of Radiation Oncology, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.
Department of Radiation Oncology, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.
出版信息
PLoS One. 2015 May 19;10(5):e0126246. doi: 10.1371/journal.pone.0126246. eCollection 2015.
PURPOSE/OBJECTIVE: Although radiotherapy is a key component of cancer treatment, its implementation into pre-clinical in vivo models with relatively small target volumes is frequently omitted either due to technical complexity or expected side effects hampering long-term observational studies. We here demonstrate how an affordable industrial micro-CT can be converted into a small animal IGRT device at very low costs. We also demonstrate the proof of principle for the case of partial brain irradiation of mice carrying orthotopic glioblastoma implants.
METHODS/MATERIALS: A commercially available micro-CT originally designed for non-destructive material analysis was used. It consists of a CNC manipulator, a transmission X-ray tube (10-160 kV) and a flat-panel detector, which was used together with custom-made steel collimators (1-5 mm aperture size). For radiation field characterization, an ionization chamber, water-equivalent slab phantoms and radiochromic films were used. A treatment planning tool was implemented using a C++ application. For proof of principle, NOD/SCID/γc(-/-) mice were orthotopically implanted with U87MG high-grade glioma cells and irradiated using the novel setup.
RESULTS
The overall symmetry of the radiation field at 150 kV was 1.04 ± 0.02%. The flatness was 4.99 ± 0.63% and the penumbra widths were between 0.14 mm and 0.51 mm. The full width at half maximum (FWHM) ranged from 1.97 to 9.99 mm depending on the collimator aperture size. The dose depth curve along the central axis followed a typical shape of keV photons. Dose rates measured were 10.7 mGy/s in 1 mm and 7.6 mGy/s in 5 mm depth (5 mm collimator aperture size). Treatment of mice with a single dose of 10 Gy was tolerated well and resulted in central tumor necrosis consistent with therapeutic efficacy.
CONCLUSION
A conventional industrial micro-CT can be easily modified to allow effective small animal IGRT even of critical target volumes such as the brain.
目的/目标：尽管放射治疗是癌症治疗的关键组成部分，但由于技术复杂性或预期的副作用会妨碍长期观察研究，在具有相对较小靶体积的临床前体内模型中实施放射治疗常常被省略。我们在此展示了如何以非常低的成本将一台经济实惠的工业微型计算机断层扫描（micro-CT）设备改造成小动物图像引导放射治疗（IGRT）设备。我们还展示了对携带原位胶质母细胞瘤植入物的小鼠进行部分脑照射情况的原理验证。
方法/材料：使用了一台最初设计用于无损材料分析的市售微型计算机断层扫描设备。它由一个计算机数控（CNC）操纵器、一个透射式X射线管（10 - 160 kV）和平板探测器组成，并与定制的钢准直器（孔径尺寸为1 - 5 mm）一起使用。为了进行辐射野表征，使用了电离室、水等效平板模体和放射变色胶片。使用C++应用程序实现了一个治疗计划工具。为了进行原理验证，将U87MG高级别胶质瘤细胞原位植入NOD/SCID/γc(-/-)小鼠体内，并使用新设置进行照射。
结果
150 kV时辐射野的整体对称性为1.04 ± 0.02%。平坦度为4.99 ± 0.63%，半值层宽度在0.14 mm至0.51 mm之间。根据准直器孔径大小，半高宽（FWHM）范围为1.97至9.99 mm。沿中心轴的剂量深度曲线遵循keV光子的典型形状。测量的剂量率在1 mm深度处为10.7 mGy/s，在5 mm深度处（5 mm准直器孔径尺寸）为7.6 mGy/s。用10 Gy的单剂量对小鼠进行治疗耐受性良好，并导致中心肿瘤坏死，与治疗效果一致。
结论
一台传统的工业微型计算机断层扫描设备可以很容易地进行改装，以实现对诸如大脑等关键靶体积的有效的小动物图像引导放射治疗。
Zotero 插件