Determination of internal target volume using selective phases of a 4-dimensional computed tomography scan
Determination of internal target volume using selective phases of a 4-dimensional computed tomography scan
复制标题
DOI：
10.1016/j.prro.2011.09.004
复制
发表时间：
2012-07-01
影响因子：
3.3
通讯作者：
Yu, Yan
中科院分区：
文献类型：
--
作者：
Cao, Junsheng;Cui, Yunfeng;Yu, Yan
目的：内部靶体积 (ITV) 通常是通过在肺癌放射治疗的 4 维计算机断层扫描 (4DCT) 研究集的 10 个阶段上绘制大体肿瘤体积 (GTV) 的轮廓来确定。本研究旨在探讨通过使用 4DCT 扫描的选择性阶段生成 ITV 的可能性。方法和材料：本研究纳入了 20 名肺癌患者的 4DCT 扫描。 GTV 在 Focal4D（CMS，圣路易斯，密苏里州）中绘制了 10 个相的轮廓。不同的 ITV 是通过包含来自选择性阶段的轮廓体积而得出的。 ITV10 是所有 10 个阶段的 GTV 的组合，并作为黄金标准卷。所有其他 ITV 均较小且位于 ITV10 之内。计算这些 ITV 与 ITV10 的体积比率，并将其用作确定不同 ITV 与 ITV10 相似性的标准。 ITV2 代表使用吸气末和呼气末 (0% + 50%) 得出的 ITV。 ITV3E 源自绘制吸气末、呼气中期和呼气末的 3 个阶段 (0% + 20% + 50%)。 ITV3I 源自绘制吸气末、吸气中期和呼气末的 3 个阶段 (0% + 70% + 50%)。 ITV4 是通过描绘吸气末、吸气中期、呼气末和呼气中期的 4 个阶段 (0% + 20% + 50% + 70%) 得出的。 ITV6E 源自呼气期间 6 个连续阶段的轮廓 (0% + 10% + 20% + 30% + 40% + 50%)。 ITV6I 源自绘制吸气过程中 6 个连续阶段的轮廓 (50% + 60% + 70% + 80% + 90% + 0%)。计算并比较了 ITV 的体积。结果：ITV6I 与 ITV10 表现出极好的一致性（体积比 ITV6I/ITV10 = 0.975）。 ITV4 和 ITV6E 与 ITV10 表现出良好的一致性（ITV6E/ITV10 = 0.939，ITV4/ITV10 = 0.944）。体积比ITV3I/ITV10和ITV3E/ITV10分别为0.927和0.906。 ITV2 与 ITV10 不太一致 (ITV2/ITV10 = 0.888)。结论：绘制吸入过程中所有阶段的轮廓可以很好地估计 ITV。然而，如果仅在 2 个极端相位上绘制轮廓，则 ITV 可能会被低估。 (C) 2012 年美国放射肿瘤学会。由爱思唯尔公司出版。保留所有权利。
Purpose: Internal target volume (ITV) is frequently determined by contouring of gross tumor volumes (GTV) on 10 phases of a 4-dimensional computed tomography (4DCT) study set for lung cancer radiotherapy. This study aimed to investigate the possibility of generating ITV by using selective phases of a 4DCT scan.Methods and Materials: The 4DCT scans of 20 patients with lung cancer were included in this study. GTVs were contoured on 10 phases in Focal4D (CMS, St Louis, MO). Different ITVs were derived by encompassing volumes of contours from selective phases. ITV10 was the combination of GTVs on all of the 10 phases and served as the gold standard volume. All of the other ITVs were smaller and within ITV10. The ratios of the volumes of these ITVs to ITV10 were calculated and used as a criterion to determine the similarity of different ITVs to ITV10. ITV2 represented the ITV derived by using end-inhalation and end-exhalation (0% + 50%). ITV3E was derived from contouring the 3 phases at end-inhalation, mid-exhalation, and end-exhalation (0% + 20% + 50%). ITV3I was derived from contouring the 3 phases at end-inhalation, mid-inhalation, and endexhalation (0% + 70% + 50%). ITV4 was derived by contouring the 4 phases at end-inhalation, midinhalation, end-exhalation, and mid-exhalation (0% + 20% + 50% + 70%). ITV6E was derived from contouring the 6 consecutive phases during exhalation (0% + 10% + 20% + 30% + 40% + 50%). ITV6I was derived from contouring the 6 consecutive phases during inhalation (50% + 60% + 70% + 80% + 90% + 0%). The volumes of ITVs were calculated and compared.Results: ITV6I showed excellent agreement with ITV10 (volume ratio ITV6I/ITV10 = 0.975). ITV4 and ITV6E showed good agreement with ITV10 (ITV6E/ITV10 = 0.939, ITV4/ITV10 = 0.944). The volume ratios ITV3I/ITV10 and ITV3E/ITV10 were 0.927 and 0.906, respectively. ITV2 did not agree well with ITV10 (ITV2/ITV10 = 0.888).Conclusions: Contouring all phases during inhalation provides a good estimate of the ITV. However, the ITV may be underestimated if only contouring on 2 extreme phases. (C) 2012 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved.