Dosimetric advantages of postoperative radiotherapy in flattening filter-free mode for left-sided breast cancer(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2021年第3期
- Page:
- 281-286
- Research Field:
- 医学放射物理
- Publishing date:
Info
- Title:
- Dosimetric advantages of postoperative radiotherapy in flattening filter-free mode for left-sided breast cancer
- Author(s):
- LUO Hongying1; 2; ZHOU Jianliang1; SHAN Guoping2; SHAO Kainan2; YANG Yiwei2; ZHOU Xia3
- 1. School of Nuclear Science and Technology, University of South China, Hengyang 421001, China 2. Department of Radiation Physics, Cancer Hospital of the University of Chinese Academy of Sciences (Zhejiang Cancer Hospital), Hangzhou 310022, China 3. Department of Radiotherapy, Cancer Hospital of the University of Chinese Academy of Sciences (Zhejiang Cancer Hospital), Hangzhou 310022, China
- Keywords:
- Keywords: breast cancer flatten filter-free mode volumetric modulated arc therapy dosimetric
- PACS:
- R318；R811.1
- DOI:
- DOI:10.3969/j.issn.1005-202X.2021.03.003
- Abstract:
- Abstract: Objective To compare the dosimetric characteristics of volumetric modulated arc therapy (VMAT) plan in flattening filter (FF) mode and flattening filter?ree (FFF) mode, and to analyze the dosimetric advantages of FFF-VMAT. Methods Ten patients with left-sided breast cancer after total resection from 2019 to 2020 were randomly selected. The same prescription dose of 50 Gy was given to the planning target volume (PTV) of the same patient by two modes separately, and two kinds of plans, namely FFF-VMAT plan and FF-VMAT plan, were designed on RayStation planning system. When the clinical requirements were met, the dosimetric characteristics, total monitor units and total delivery time were compared between FFF-VMAT and FF-VMAT. Results Except for the D98% of PTV which was lower in FFF-VMAT than that in FF-VMAT (P=0.007), there was no significant difference between two groups in the D95%, D2%, CI and HI of PTV (P>0.05). FFF mode was superior to FF mode in protection of affected lung, the whole lungs, heart, spinal cord and anterior coronary artery (P<0.05), and compared with those in FF-VMAT, the average dose delivered to the affected lung and heart in FFF-VMAT were decreased by 9.59% and 12.20%, respectively. The differences between FF-VMAT and FFF-VMAT in sparing of the healthy lung, brachial plexus and normal tissues were trivial, without statistical significance (P>0.05). The total monitor units of FFF-VMAT was 1.30 times of that of FF-VMAT, and the total delivery time was shortened to 87.15% of FF-VMAT. Conclusion On the premise that the treatment plans of both groups can meet the clinical treatment requirements, FFF mode can significantly reduce the radiation dose delivered to organs-at-risk and normal tissues. Although the total monitor units in FFF-VMAT is increased, the treatment time is shortened. Therefore, the treatment efficiency of FFF mode is better than that of FF mode.
Last Update: 2021-03-30