ITV-Based Robust Optimization for VMAT Planning of Stereotactic Body Radiation Therapy of Lung Cancer
ITV-Based Robust Optimization for VMAT Planning of Stereotactic Body Radiation Therapy of Lung Cancer
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DOI：
10.1016/j.prro.2018.08.005
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发表时间：
2019-01-01
影响因子：
3.3
通讯作者：
Li, Zuofeng
中科院分区：
文献类型：
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作者：
Liang, Xiaoying;Zheng, Dandan;Li, Zuofeng
目的：在肺癌立体定向全身放射治疗(SBRT)中，使用计划靶体积(PTV)来解释设置的不确定性一直受到质疑，因为PTV的很大一部分包含低密度肺组织。本研究的目的是：(1)探讨稳健优化在肺SBRT容积调节性弧形治疗计划中考虑设置不确定性的可行性；(2)与传统的基于PTV的优化计划相比，评估稳健优化计划的潜在的正常组织保留效益。方法和材料：本研究以体模和患者为研究对象。对于每个患者或模体，生成了2个SBRT肺容量调节式弧形治疗计划，包括基于PTV(基于PTV的计划)的优化计划和基于稳健优化的ITV(基于ITV的计划)的第二个计划，其中PTV(基于PTV的计划)具有5 mm的内部靶体积(ITV)至PTV的边缘，设置不确定度为+/-5 mm。在15个模拟5 mm设置误差的情况下，在ITV D99上评估了目标覆盖。结果：与基于PTV的计划相比，基于ITV的稳健优化计划在保持体模和患者设置误差场景下的剂量覆盖范围的同时，获得了较低的正常肺组织剂量、较低的中高剂量向体内泄漏和较低的积分剂量。结论：基于ITV的稳健优化方案在考虑设置不确定性的SBRT计划中是可行的。需要进一步的临床研究来证实这种新方法的临床有效性。(C)2018年美国放射肿瘤学学会。爱思唯尔公司出版，版权所有。
Purpose: Using planning target volume (PTV) to account for setup uncertainties in stereotactic body radiation therapy (SBRT) of lung cancer has been questioned because a significant portion of the PTV contains low-density lung tissue. The purpose of this study is to (1) investigate the feasibility of using robust optimization to account for setup uncertainties in volumetric modulated arc therapy plan for lung SBRT and (2) evaluate the potential normal tissue-sparing benefit of a robust optimized plan compared with a conventional PTV-based optimized plan.Methods and materials: The study was conducted with both phantom and patient cases. For each patient or phantom, 2 SBRT lung volumetric modulated arc therapy plans were generated, including an optimized plan based on the PTV (PTV-based plan) with a 5-mm internal target volume (ITV)-to-PTV margin and a second plan based on robust optimization of ITV (ITV-based plan) with +/- 5-mm setup uncertainties. The target coverage was evaluated on ITV D99 in 15 scenarios that simulated a 5-mm setup error. Dose-volume information on normal lung tissue, intermediate-to-high dose spillage, and integral dose was evaluated.Results: Compared with PTV-based plans, ITV-based robust optimized plans resulted in lower normal lung tissue dose, lower intermediate-to-high dose spillage to the body, and lower integral dose, while preserving the dose coverage under setup error scenarios for both phantom and patient cases.Conclusions: Using ITV-based robust optimization, we have shown that accounting for setup uncertainty in SBRT planning is feasible. Further clinical studies are warranted to confirm the clinical effectiveness of this novel approach. (C) 2018 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved.