Position shifts and volume changes of pelvic and para-aortic nodes during IMRT for patients with cervical cancer
Position shifts and volume changes of pelvic and para-aortic nodes during IMRT for patients with cervical cancer
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DOI：
10.1016/j.radonc.2014.05.013
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发表时间：
2014-06-01
影响因子：
5.7
通讯作者：
Jurgenliemk-Schulz, Ina M.
中科院分区：
文献类型：
--
作者：
Schippers, Maaike G. A.;Bol, Gijsbert H.;Jurgenliemk-Schulz, Ina M.
背景和目的：为了评估体积变化和位置的变化，并在调强放射治疗（IMRT）的治疗边缘的盆腔和腹主动脉旁淋巴结的晚期cervicancer.Materials和方法：17例患者的MR图像上可见的淋巴结进行了T2加权MR扫描之前和每周在IMRT的过程中。在所有扫描中描绘了39个盆腔和主动脉旁淋巴结。容的体积和位置变化的边缘采取从边界的结节体积在六个主要的directions.Results：从治疗前的情况下，第4周的结节体积回归平均为58%（范围：11.7%增加到100%减少）。治疗前扫描和第1-3周扫描之间的结节体积部分增加，但在第4周，除一个外，所有结节均消退。在淋巴结体积周围，需要手动导出ITV边界，以涵盖所有淋巴结的95%，其中ITV边界占体积变化以及向内侧、外侧、前、后、上级和下方方向的7.0、4.0、7.0、8.0、7.0和9.0 mm的位置移位。我们使用每周一次的MR扫描来获得不均匀的边缘，以适应治疗期间淋巴结体积和位置的变化。在计划外射束放射治疗（EBRT）增强时，应考虑这些裕度，特别是对于高度适形的增强技术。(C)2014爱思唯尔爱尔兰有限公司版权所有。
Background and purpose: To evaluate volume changes and position shifts and their contribution to treatment margins of pelvic and para-aortic lymph nodes during Intensity Modulated Radiation Therapy (IMRT) for advanced cervical cancer.Materials and methods: Seventeen patients with visible nodes on MR images underwent T2-weighted MR scans before and weekly during the course of IMRT. Thirty-nine pelvic and para-aortic nodes were delineated on all scans. Margins accommodating for volume and position changes were taken from the boundaries of the nodal volumes in the six main directions.Results: Nodal volume regression from the pre-treatment situation to week 4 was 58% on average (range: 11.7% increase to 100% decrease). Nodal volumes partly increased between the pre-treatment scans and the scans in weeks 1-3, but in week 4 all nodes except one had regressed. Around the nodal volumes manually derived ITV margins accounting for volume changes and position shifts of 7.0, 4.0, 7.0, 8.0, 7.0 and 9.0 mm to the medial, lateral, anterior, posterior, superior and inferior directions were needed to cover 95% of all nodes.Conclusions: We used weekly MR scans to derive inhomogeneous margins that accommodate for nodal volume and position changes during treatment. These margins should be taken into consideration when planning external beam radiotherapy (EBRT) boosts, especially for highly conformal boosting techniques. (C) 2014 Elsevier Ireland Ltd. All rights reserved.