Repositioning accuracy of a commercially available thermoplastic mask system
Repositioning accuracy of a commercially available thermoplastic mask system
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DOI：
10.1016/j.radonc.2004.03.003
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发表时间：
2004-06-01
影响因子：
5.7
通讯作者：
Herman, TS
中科院分区：
文献类型：
--
作者：
Fuss, M;Salter, BJ;Herman, TS
背景和目的：为了评价市售热塑性面罩系统用于单剂量放射外科治疗和分次治疗courses.Patients和方法的重新定位精度：分析Raycast（C）-HP面罩系统（Orfit Industries，维涅海姆，Belgium）的重新定位精度。22例患者接受调强放射治疗（IMRT）或调强放射外科（IMRS）治疗43处颅内病变，在治疗过程中重复进行CT成像，或在放射外科手术前立即进行位置对照。我们在连续重复CT对照中评价了多个解剖标志坐标及其各自的移位。迭代优化算法允许计算每次重复CT的靶等中心平移的x、y和z分量，以及相应CT数据集中的旋转。除了绝对的目标等中心平移，总的幅度矢量（即总和矢量）的等中心运动计算沿着与患者旋转的三个主轴axis.Results：五十五个控制CT数据集进行了分析，目标等中心的各自的位置相对于原始的治疗计划CT模拟。x、y和z方向的平均靶等中心平移分别为0.74 +/- 0.53、0.75 +/- 0.60和0.93 +/- 0.78 mm。绕x、y和z轴的平均旋转分别为0.67 +/- 0.66、0.61 +/- 0.63和0.67 +/- 0.61度。等中心平移的中值和平均幅度向量分别为1.28和1.59 +/- 0.84 mm。第一次摆位控制的准确性分析，代表放射外科治疗的摆位准确性，与整个分次放射治疗过程中的摆位准确性相比，在统计学上是等效的（P = 0.15），从而表明在整个治疗course.Conclusions设置准确性没有可测量的恶化：分析Orfit热塑性口罩系统进行有利相比，其他面具固定系统，同行评审的重新定位数据存在。虽然该系统用于分次疗程的性能被认为是极好的，在我们的诊所中，使用这种用于放射外科固定的面罩系统受到额外的质量保证措施的约束，以禁止对大于2 mm的靶脱位进行治疗。本研究中的测量数据应使该系统的用户能够为计划靶的生成分配适当的裕度。卷(C)2004爱思唯尔爱尔兰有限公司保留所有权利。
Background and purpose: To evaluate the repositioning accuracy of a commercially available thermoplastic mask system for single dose radiosurgery treatments and fractionated treatment courses.Patients and methods: The repositioning accuracy of the Raycast(C)-HP mask system (Orfit Industries, Wijnegem, Belgium) was analyzed. Twenty-two patients that were treated by intensity-modulated radiation therapy (IMRT) or intensity modulated radiosurgery (IMRS) for 43 intracranial lesions, underwent repeated CT imaging during their course of treatment, or as a positional control immediately before radiosurgery. We evaluated multiple anatomical landmark coordinates and their respective shifts in consecutive repeated CT-controls. An iterative optimization algorithm allowed for the calculation of the x, y and z-components of translation of the target isocenter(s) for each repeated CT, as well as rotation in the respective CT data sets. In addition to absolute target isocenter translation, the total magnitude vector (i.e. sum-vector) of isocenter motion was calculated along with patient rotations about the three principle axes.Results: Fifty-five control CT datasets were analyzed for the target isocenter's respective position relative to the original treatment planning CT simulation. Mean target isocenter translation was 0.74 +/- 0.53, 0.75 +/- 0.60 and 0.93 +/- 0.78 mm in x, y and z-directions, respectively. Mean rotation about the x, y and z-axes was 0.67 +/- 0.66, 0.61 +/- 0.63 and 0.67 +/- 0.61 degrees, respectively. The respective median and mean magnitude vectors of isocenter translation were 1.28 and 1.59 +/- 0.84 mm. Analysis of the accuracy of the first setup control, representative of setup accuracy for radiosurgery treatments, compared with setup accuracy throughout a fractionated radiation treatment course were statistically equivalent (P = 0.15), thus indicating no measurable deterioration of setup accuracy throughout the treatment course.Conclusions: The analyzed Orfit thermoplastic mask system performed favorably compared with other mask immobilization systems for which peer-reviewed repositioning data exist. While the performance of the system for fractionated treatment courses was considered to be excellent, use of this mask system for radiosurgery immobilization in our clinic is subject to additional quality assurance measures to prohibit the delivery of treatments with target dislocations larger than 2 mm. The measured data in the present study should enable the users of this system to assign appropriate margins for the generation of planning target volumes. (C) 2004 Elsevier Ireland Ltd. All rights reserved.