An experimental demonstration of a new type of proton computed tomography using a novel silicon tracking detector
An experimental demonstration of a new type of proton computed tomography using a novel silicon tracking detector
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DOI：
10.1118/1.4965809
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发表时间：
2016-11-01
期刊：
影响因子：
3.8
通讯作者：
Allinson, N. M.
中科院分区：
文献类型：
--
作者：
Taylor, J. T.;Poludniowski, G.;Allinson, N. M.
目的：使用质子束的X线摄影和断层摄影有望为质子治疗的图像引导和治疗计划带来益处。描述了一种新型质子跟踪探测器，并报道了在治疗设施上的实验演示。一种新型的质子CT重建相对的“散射功率”，而不是“阻止功率”也被证明。值得注意的是，这种新类型的成像不需要测量的剩余能量的质子。方法：一个大面积，硅微带跟踪器具有高的空间和时间分辨率已开发的质子放射治疗验证和剂量学应用财团和委托使用质子束iThemba实验室，医疗放射部，南非。该跟踪器由12个硅平面组成，使用高能物理技术开发，每个平面的有效面积类似于10 × 10 cm，分为2048个微带。跟踪器被组织成四个独立的单元，每个单元包含三个彼此成60度的探测器，创建一个chi-mu-nu坐标系。成对的跟踪单元用于重建质子进入和离开包含组织等效插入物的体模的顶点。通过测量每个质子的位置和方向之前和之后的幻影，每个质子通过一个object. Results的非线性路径可以reconstruct.Results：实验结果报告跟踪质子的路径与初始能量为125和191 MeV。通过将直径为75 mm的球形体模定位在跟踪器的入口和出口探测器之间对其进行成像。使用单个质子的位置和方向来创建射束的角分布和2D注量图。这些结果被收购为36等间距的投影跨越180度，允许，第一次，实验CT图像的基础上的相对散射功率的质子reconstruct.Conclusions：成功跟踪质子通过一个厚的目标（幻影）已经证明，本文讨论的跟踪器可以提供精确的方向信息，需要执行质子射线照相和断层扫描。当与范围望远镜同步时，这可以使质子CT图像的阻止能力重建成为可能。此外，通过测量许多质子通过体模的偏转，证明了仅基于该跟踪信息就可以重建一种新的CT图像（散射功率）。(C)2016年作者。
Purpose: Radiography and tomography using proton beams promise benefit to image guidance and treatment planning for proton therapy. A novel proton tracking detector is described and experimental demonstrations at a therapy facility are reported. A new type of proton CT reconstructing relative "scattering power" rather than "stopping power" is also demonstrated. Notably, this new type of imaging does not require the measurement of the residual energies of the protons.Methods: A large area, silicon microstrip tracker with high spatial and temporal resolution has been developed by the Proton Radiotherapy Verification and Dosimetry Applications consortium and commissioned using beams of protons at iThemba LABS, Medical Radiation Department, South Africa. The tracker comprises twelve planes of silicon developed using technology from high energy physics with each plane having an active area of similar to 10x10 cm segmented into 2048 microstrips. The tracker is organized into four separate units each containing three detectors at 60 degrees to one another creating an chi-mu-nu coordinate system. Pairs of tracking units are used to reconstruct vertices for protons entering and exiting a phantom containing tissue equivalent inserts. By measuring the position and direction of each proton before and after the phantom, the nonlinear path for each proton through an object can be reconstructed.Results: Experimental results are reported for tracking the path of protons with initial energies of 125 and 191 MeV. A spherical phantom of 75 mm diameter was imaged by positioning it between the entrance and exit detectors of the tracker. Positions and directions of individual protons were used to create angular distributions and 2D fluence maps of the beam. These results were acquired for 36 equally spaced projections spanning 180 degrees, allowing, for the first time, an experimental CT image based upon the relative scattering power of protons to be reconstructed.Conclusions: Successful tracking of protons through a thick target (phantom) has demonstrated that the tracker discussed in this paper can provide the precise directional information needed to perform proton radiography and tomography. When synchronized with a range telescope, this could enable the reconstruction of proton CT images of stopping power. Furthermore, by measuring the deflection of many protons through a phantom, it was demonstrated that it is possible to reconstruct a new kind of CT image (scattering power) based upon this tracking information alone. (C) 2016 Author(s).