Target volume shape variation during irradiation of rectal cancer patients in supine position: Comparison with prone position
Target volume shape variation during irradiation of rectal cancer patients in supine position: Comparison with prone position
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DOI：
10.1016/j.radonc.2009.08.007
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发表时间：
2009-11-01
影响因子：
5.7
通讯作者：
Marijnen, Corrie
中科院分区：
文献类型：
--
作者：
Nijkamp, Jasper;de Jong, Rianne;Marijnen, Corrie
目的：定量分析直肠癌患者仰卧位5×5GY照射后直肠系膜形态变化，并与俯卧位比较。方法：对28例直肠癌患者进行仰卧位CT平扫和5次锥束CT扫描。所有扫描均显示CTV的直肠系膜部分(MesoRect)。形状变化通过PCT-和CBCT轮廓之间的距离来量化，并在在线设置校正后存储在表面图中。分别对男性和女性患者的数据进行分析，并与俯卧位患者的数据进行比较。结果：系统的1-8 mm(1SD)和随机的1-5 mm的形状变化范围很大，与俯卧位患者相当。随机形态变异在男性和女性患者中具有可比性，而系统变异在女性患者中大3 mm。结论：中枢神经形态变异是实质性的，不同性别患者之间存在差异。然而，仰卧位和俯卧位之间的差异很小。临床切缘应在颅尾轴线、前后方向和性别上进行区分。即使在使用在线设置更正的情况下，也应增加边距。由于俯卧位和仰卧位治疗的边际差异很小，应根据危险器官的剂量来确定设置的选择。(C)2009爱思唯尔爱尔兰有限公司。保留所有权利。放射治疗与肿瘤学93(2009)285-292
Purpose: To quantify the inter-fraction shape variation of the mesorectum for rectal cancer patients treated with 5 x 5 Gy in supine position and compare it to variation in prone position.Methods and materials: For 28 patients a planning CT (pCT) and five daily cone-beam-CT (CBCT) scans were acquired in supine position. The mesorectal part of the CTV (MesoRect) was delineated on all scans. The shape variation was quantified by the distance between the pCT- and the CBCT delineations and stored in surface maps after online setup correction. Data were analyzed for male and female patients separately and compared to prone data.Results: A large range of systematic, 1-8 mm (1SD), and random, 1-5 mm, shape variation was found, comparable to prone patients. Random-shape variation was comparable for male and female patients, while systematic variation was 3 mm larger for female patients.Conclusions: Shape variation of the MesoRect is substantial, heterogeneous and different between male and female patients. Differences between supine and prone orientation, however, are small. Clinical margins should be differentiated in position along the cranio-caudal axis, in anterior-posterior direction and for gender. Margins should also be increased, even when online setup correction is used. Due to the small margin differences between prone and supine treatments, the setup choice should be determined on dose to the organs at risk. (C) 2009 Elsevier Ireland Ltd. All rights reserved. Radiotherapy and Oncology 93 (2009) 285-292