Ding Zhen, Zeng Qi, Kang Kailian, Xu Meiling, Xiang Xiaoyong, Liu Chenbin
Department of Radiation Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital & Shenzhen Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 113 Baohe Road, Longgang District, Shenzhen 518116, China.
Bioengineering (Basel). 2022 Mar 24;9(4):131. doi: 10.3390/bioengineering9040131.
We aim to evaluate the robustness of multi-field IMRT and VMAT plans to target motion for left-sided BC radiotherapy.
The 7-field hybrid IMRT (7F-H-IMRT) and 2-arc VMAT (2A-VMAT) plans were generated for ten left-sided BC patients. Shifts of 3 mm, 5 mm, and 10 mm in six directions were introduced and the perturbed dose distributions were recalculated. The dose differences (∆D) of the original plan and perturbed plan corresponded to the plan robustness for the structure.
Higher ∆D, ∆D, and ∆D of CTV were observed in 2A-VMAT plans, which induced higher tumor control probability reductions. A higher ∆Dmean of CTV Boost was found in 7F-H-IMRT plans despite lower ∆D and ∆D. Shifts in the S-I direction exerted the largest effect on CTV and CTV Boost. Regarding OARs, shifts in R, P, and I directions contributed to increasing the received dose. The 2A-VMAT plans performed better dose sparing, but had a higher robustness in a high-dose volume of the left lung and heart. The 2A-VMAT plans decreased the max dose of LAD but exhibited lower robustness.
The 2A-VMAT plans showed higher sensitivity to position deviation. Shifts in the S-I direction exerted the largest effect for CTV and CTV Boost.
我们旨在评估多野调强放疗（IMRT）和容积旋转调强放疗（VMAT）计划针对左侧乳腺癌放疗中靶区运动的稳健性。
为10例左侧乳腺癌患者生成7野混合IMRT（7F-H-IMRT）和2弧VMAT（2A-VMAT）计划。在六个方向上引入3毫米、5毫米和10毫米的移位，并重新计算受扰后的剂量分布。原始计划和受扰计划的剂量差异（∆D）对应于该结构的计划稳健性。
在2A-VMAT计划中观察到CTV的∆D、∆D和∆D更高，这导致肿瘤控制概率降低得更多。尽管7F-H-IMRT计划的∆D和∆D较低，但CTV增敏区的∆Dmean更高。头脚方向的移位对CTV和CTV增敏区影响最大。关于危及器官（OARs），右、后和内方向的移位导致所接受剂量增加。2A-VMAT计划的剂量 sparing效果更好，但在左肺和心脏的高剂量体积方面具有更高的稳健性。2A-VMAT计划降低了左前降支（LAD）的最大剂量，但稳健性较低。
2A-VMAT计划对位置偏差表现出更高的敏感性。头脚方向的移位对CTV和CTV增敏区影响最大。
