Daily ultrasound-based image-guided targeting for radiotherapy of upper abdominal malignancies
Daily ultrasound-based image-guided targeting for radiotherapy of upper abdominal malignancies
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DOI：
10.1016/j.ijrobp.2003.12.030
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发表时间：
2004-07-15
影响因子：
7
通讯作者：
Thomas, CR
中科院分区：
文献类型：
--
作者：
Fuss, M;Salter, BJ;Thomas, CR
目的：开发和实施一种使用基于立体定向超声(US)的图像引导靶向装置(BAT)来精确对准上腹部调强放疗(IMRT)靶区的策略。由于US可能不能很好地显示这类目标的轮廓，因此我们提出了一种使用邻近的血管引导结构来替代目标位置的方法。方法与材料：2000年10月至2003年6月，对62例胆管癌、胆囊癌、肝细胞癌、肝转移癌、胰腺癌、神经母细胞瘤和其他腹部及腹膜后肿瘤患者行序贯断层放射治疗，其中胆囊癌10例，肝细胞癌11例，胰腺癌20例。靶区体积(TV)和危险器官在增强CT数据集中描绘。此外，还描绘了与电视有密切解剖关系的血管引导结构或电视内的血管引导结构。在整个调强放射治疗过程中，在日常治疗定位过程中采集超声BAT图像。除了通常用于US靶向的解剖结构(例如，存在风险的TV和剂量限制器官)外，引导结构的CT轮廓被叠加到实时获取的轴向和矢状位US图像上，并根据系统指示进行目标位置调整。我们报告了与基于皮肤印记的设置相比，BAT导出的三个主要房间轴上的位移分布，以及执行BAT对齐所需的时间。在15名患者中，通过比较治疗模拟CT和US靶向CT套件后对照CT研究的器官和基准位置，评估了该方法改善靶向的能力。结果：总共尝试了1337次BAT对准。在56个设置(4.2%)中，超声图像没有用处，主要是因为结肠和胃空气的每日变化导致能见度有限。在肝内肿瘤和虚弱患者中，超声成像是方便的。X、y、z方向平均+/-SD移位分别为4.9+/-4.35 mm、6.0+/-5.31 mm、6.0+/-6.7 mm。三维矫正的平均幅度向量为11.4+/-7.6 mm。经过震级>；10、>；15和>；20 mm校正的日对齐比例分别为48.9%、25.1%和12.7%。主方向位移的大小以及位移的三维向量在p处具有统计学意义(对照零假设进行检验)。
Purpose: Development and implementation of a strategy to use a stereotactic ultrasound (US)-based image-guided targeting device (BAT) to align intensity-modulated radiotherapy (IMRT) target volumes accurately in the upper abdomen. Because the outlines of such targets may be poorly visualized by US, we present a method that uses adjacent vascular guidance structures as surrogates for the target position. We assessed the potential for improvement of daily repositioning and the feasibility of daily application.Methods and Materials: A total of 62 patients were treated by sequential tomotherapeutic IMRT between October 2000 and June 2003 for cholangiocarcinoma and gallbladder carcinoma (n = 10), hepatocellular carcinoma (n = 10), liver metastases (n = 11), pancreatic carcinoma (it = 20), neuroblastoma (n = 3), and other abdominal and retroperitoneal tumors (n = 8). The target volumes (TVs) and organs at risk were delineated in contrast-enhanced CT data sets. Additionally, vascular guidance structures in close anatomic relation to the TV, or within the TV, were delineated. Throughout the course of IMRT, US BAT images were acquired during daily treatment positioning. In addition to the anatomic structures typically used for US targeting (e.g., the TV and dose-limiting organs at risk), CT contours of guidance structures were superimposed onto the real-time acquired axial and sagittal US images, and target position adjustments, as indicated by the system, were performed accordingly. We report the BAT-derived distribution of shifts in the three principal room axes compared with a skin-mark-based setup, as well as the time required to perform BAT alignment. The capability of the presented method to improve target alignment was assessed in 15 patients by comparing the organ and fiducial position between the respective treatment simulation CT with a control CT study after US targeting in the CT suite.Results: A total of 1,337 BAT alignments were attempted. US images were not useful in 56 setups (4.2%), mainly because of limited visibility due to daily variations in colonic and gastric air. US imaging was facilitated in intrahepatic tumors and asthenic patients. The mean +/-SD shift from the skin mark position was 4.9 +/- 4.35, 6.0 +/- 5.31, and 6.0 +/- 6.7 mm in the x, y, and z direction, respectively. The mean magnitude vector of three-dimensional alignment correction was 11.4 +/- 7.6 mm. The proportion of daily alignments corrected by a magnitude of >10, >15, and >20 mm was 48.9%, 25.1%, and 12.7%, respectively. The magnitude of shifts in the principal directions, as well as the three-dimensional vector of displacement, was statistically significant (test against the zero hypothesis) at p