Rapid design of breast cancer volumetric modulated arc therapy plan based on TrueBeam platform [基于TrueBeam 平台设计左乳腺癌术后放疗VMAT 计划]

作者：Su J.-H.; Dong Y.-X.; Zhu Y.; Wei X.-P.^*; Huang X.-W.

来源：Chinese Journal of Cancer Prevention and Treatment, 2022, 29(24): 1746-1752.

DOI：10.16073/j.cnki.cjcpt.2022.24.05

• deep inhalation breath holding
• left breast cancer
• radiotherapy
• volume modulated arc therapy

Objective To explore a simpler and more efficient way to perform a four-arcs volumetric modulated arc therapy (VMAT) planning on breast cancer by using the TrueBeam treatment platform, so as to lower the plan design difficulty and doses to organs at risk (OARs). Methods Totally 24 post-surgery breast cancer cases treated with the deep inhalation breath holding (DIBH) were selected from May 11, 2020 to March 1, 2022 in the Jinshazhou Hospital of Guangzhou University of Chinese Medicine. The target included supraclavicular regions and the thoracic parts. Varian Eclipse 15. 6 treatment planning system was used for delineation of the special auxiliary structures and setting for four arc fields. The VMAT plan (VMAT_limit) for the left breast was redesigned using fundamental and fixed optimization objectives and were compared with the original VMAT plan (VMAT_clmic), including the conformity index (CI), homogeneous index (HI), maximum point dose for the target (Dmax), mean doses to OARs (Dmean), doses to the spinal cord, lungs and heart, and the total monitor units (MU). Results Compared with the VMAT clinic, VMAT limit reduced the left lung V10 volume by 7. 09% (Z= -4.13, P<0.001), left lung V5 volume by 10.93% (Z=-4. 804, P<0. 001), heart Dmean by 2. 29 by (Z-4. 578, 001), right lung V5, volume by 11. 70% (Z=-5. 691, P<0. 001), and right lung Dmean by 1. 33 Gy (Z= - 5. 815, P<0. 001). But VMAT-limit increased the volume of V5 in the contralateral breast by 8. 60% (Z =2. 423, 015), Dmean in the contralateral breast by 0. 60 Gy (Z=2. 299, 021), and MU by 132. 75 (Z=4. 227, P<0. 001). Conclusion Compared with VMAT clinic, VMAT_limit design method, while meeting the requirements of clinical dose, can reduce the volumes of V5 and V10 of the left lung, the volume of V5 of the right lung, mean doses to the right lung and to the heart;but it increases the Dmean and the volume of V5 of the contralateral breast. This method can reduce the difficulty for postoperative VMAT plan design for left breast cancers.

• 单位
  广州中医药大学; 东莞理工学院