Real-Time 3D Image Guidance Using a Standard LINAC: Measured Motion, Accuracy, and Precision of the First Prospective Clinical Trial of Kilovoltage Intrafraction Monitoring-Guided Gating for Prostate Cancer Radiation Therapy
Real-Time 3D Image Guidance Using a Standard LINAC: Measured Motion, Accuracy, and Precision of the First Prospective Clinical Trial of Kilovoltage Intrafraction Monitoring-Guided Gating for Prostate Cancer Radiation Therapy
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DOI：
10.1016/j.ijrobp.2015.10.009
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发表时间：
2016-04-01
影响因子：
7
通讯作者：
Booth, Jeremy T.
中科院分区：
文献类型：
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作者：
Keall, Paul J.;Ng, Jin Aun;Booth, Jeremy T.
目的：千伏级内监测（KIM）是一种新的实时三维图像引导方法。与以前的实时图像引导方法不同，KIM使用标准的直线加速器，无需任何额外的设备。KIM的第一个前瞻性临床试验正在进行中，用于前列腺癌放射治疗。在本文中，我们报告的测量运动的准确性和精度，使用实时KIM引导gating.Methods和材料：成像和运动信息的前200个馏分6例前列腺癌放射治疗体积调制弧治疗进行了分析。使用3 mm/5秒的动作阈值触发门控事件，其中暂停射束并调整治疗床位置以将前列腺重新对准治疗等中心点。为了量化在体内的准确性和精密度，KIM进行了比较，同时获得kV/MV三角测量为187 fractions.Results：KIM成功地用于197 200个馏分。门控事件发生在29个部分（14.5%）。在这29个部分中，射束开启时间的百分比，前列腺位移距离等中心位置>3 mm，从无KIM的73%降低到KIM引导门控的24%。>5 mm的位移从不使用KIM的16%减少到使用KIM的0%。KIM的准确度测量为
Purpose: Kilovoltage intrafraction monitoring (KIM) is a new real-time 3-dimensional image guidance method. Unlike previous real-time image guidance methods, KIM uses a standard linear accelerator without any additional equipment needed. The first prospective clinical trial of KIM is underway for prostate cancer radiation therapy. In this paper we report on the measured motion accuracy and precision using real-time KIM-guided gating.Methods and Materials: Imaging and motion information from the first 200 fractions from 6 patient prostate cancer radiation therapy volumetric modulated arc therapy treatments were analyzed. A 3-mm/5-second action threshold was used to trigger a gating event where the beam is paused and the couch position adjusted to realign the prostate to the treatment isocenter. To quantify the in vivo accuracy and precision, KIM was compared with simultaneously acquired kV/MV triangulation for 187 fractions.Results: KIM was successfully used in 197 of 200 fractions. Gating events occurred in 29 fractions (14.5%). In these 29 fractions, the percentage of beam-on time, the prostate displacement was >3 mm from the isocenter position, reduced from 73% without KIM to 24% with KIM-guided gating. Displacements >5 mm were reduced from 16% without KIM to 0% with KIM. The KIM accuracy was measured at