The Use of Cone Beam Computed Tomography for Image Guided Gamma Knife Stereotactic Radiosurgery: Initial Clinical Evaluation
The Use of Cone Beam Computed Tomography for Image Guided Gamma Knife Stereotactic Radiosurgery: Initial Clinical Evaluation
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DOI：
10.1016/j.ijrobp.2016.04.011
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发表时间：
2016-09-01
影响因子：
7
通讯作者：
Chung, Caroline
中科院分区：
文献类型：
--
作者：
Li, Winnie;Cho, Young-Bin;Chung, Caroline
目的：本研究使用锥形束计算机断层扫描（CBCT）测量使用Leksell伽玛刀（GK）进行颅内立体定向放射手术（SRS）时的偏移间和偏移内不确定性。方法和材料：采用一种适用于GK放射外科治疗单元的新型CBCT系统，在研究伦理委员会批准的前瞻性临床试验的背景下，在每次治疗之前和之后立即获取CBCT图像。患者被固定在Leksell坐标系（LCF）中，用于体积CBCT成像和GK-SRS传送。每次CBCT扫描测量患者颅骨相对于立体定向参考（干涉运动）的相对位移。使用治疗前后CBCT扫描的差异来确定屈光内运动。结果：我们分析了20例接受SRS治疗的LCF患者的20个治疗前和17个治疗后的CBCT扫描。左右、前后、颅侧方向的平均平移预处理设置误差+/-标准差分别为-0.19 +/- 0.32、0.06 +/- 0.27和-0.23 +/- 0.2 mm，最大值分别为-0.74、-0.53和-0.68 mm。治疗前后CBCT扫描的平均时间为82分钟（范围27-170分钟），LCF在左右、前后和颅脑方向的平均偏移误差+/-标准差分别为-0.03 +/- 0.05、-0.03 +/- 0.18和-0.03 +/- 0.12 mm。结论：在原型图像引导下的GK完美装置上使用CBCT，我们能够使用有创框架测量GK- srs的眼球间和眼球内位置变化。在图像引导放射治疗的时代，使用CBCT图像引导框架和非框架为基础的固定系统可以作为一个有用的质量保证工具。我们的初步测量可以指导应用可实现的阈值之间和内部的差异，当移动到一个无帧的方法。(C) 2016年作者。Elsevier Inc.出版。
Purpose: The present study used cone beam computed tomography (CBCT) to measure the inter- and intrafraction uncertainties for intracranial stereotactic radiosurgery (SRS) using the Leksell Gamma Knife (GK).Methods and Materials: Using a novel CBCT system adapted to the GK radiosurgery treatment unit, CBCT images were acquired immediately before and after treatment for each treatment session within the context of a research ethics board-approved prospective clinical trial. Patients were immobilized in the Leksell coordinate frame (LCF) for both volumetric CBCT imaging and GK-SRS delivery. The relative displacement of the patient's skull to the stereotactic reference (interfraction motion) was measured for each CBCT scan. Differences between the pre- and post-treatment CBCT scans were used to determine the intrafraction motion.Results: We analyzed 20 pre- and 17 post-treatment CBCT scans in 20 LCF patients treated with SRS. The mean translational pretreatment setup error +/- standard deviation in the left-right, anteroposterior, and craniocaudal directions was -0.19 +/- 0.32, 0.06 +/- 0.27, and -0.23 +/- 0.2 mm, with a maximum of -0.74, -0.53, and -0.68 mm, respectively. After an average time between the pre- and post-treatment CBCT scans of 82 minutes (range 27-170), the mean intrafraction error +/- standard deviation for the LCF was -0.03 +/- 0.05, -0.03 +/- 0.18, and -0.03 +/- 0.12 mm in the left-right, anteroposterior, and craniocaudual direction, respectively.Conclusions: Using CBCT on a prototype image guided GK Perfexion unit, we were able to measure the inter- and intrafraction positional changes for GK-SRS using the invasive frame. In the era of image guided radiation therapy, the use of CBCT image guidance for both frame- and non-frame-based immobilization systems could serve as a useful quality assurance tool. Our preliminary measurements can guide the application of achievable thresholds for inter- and intrafraction discrepancy when moving to a frameless approach. (C) 2016 The Authors. Published by Elsevier Inc.