| Fuli Zhang,Weidong Xu,Huayong Jiang,Yadi Wang,Junmao Gao,Qingzhi Liu. Dosimetric evaluation of VMAT radiation therapy technique for breast cancer after conservative surgery based on three different types of multileaf collimators. Oncol Transl Med, 2018, 4: 208-214. |
| Dosimetric evaluation of VMAT radiation therapy technique for breast cancer after conservative surgery based on three different types of multileaf collimators |
| Received:September 17, 2018 Revised:November 26, 2018 |
| View Full Text View/Add Comment Download reader |
| KeyWord:multileaf collimator; leaf width; volumetric modulated arc therapy (VMAT); breast cancer; agility; MLCi2; beam modulator (BM) |
| Author Name | Affiliation | E-mail | | Fuli Zhang | Radiation Oncology Department,The PLA Army General Hospital of China,No. 5,Nanmencang,Dongcheng | radiozfli@163.com | | Weidong Xu | Radiation Oncology Department,The PLA Army General Hospital of China,No. 5,Nanmencang,Dongcheng | | | Huayong Jiang | Chinese PLA Army General Hospital, Beijing 100700, China | | | Yadi Wang | Chinese PLA Army General Hospital, Beijing 100700, China | | | Junmao Gao | Chinese PLA Army General Hospital, Beijing 100700, China | | | Qingzhi Liu | Chinese PLA Army General Hospital, Beijing 100700, China | |
|
| Hits: 6204 |
| Download times: 7030 |
| Abstract: |
| Objective Radiotherapy combined with conservative surgery plays an important role in the treatment
of early-stage breast cancer. Volumetric modulated arc therapy (VMAT) has been introduced into clinical
practice. The purpose of this study was to investigate the dosimetric effects of different multileaf collimators
(MLC) on VMAT radiotherapy plans for treating breast cancer.
Methods Fifteen breast cancer patients who were treated using a conventional technique in our
department were selected to participate in this retrospective analysis. VMAT plans based on three types of
Elekta MLCs [Beam Modulator (BM) with 4-mm leaf width, Agility with 5-mm leaf width and MLCi2 with 10-
mm leaf width] were independently generated for each patient. Plan comparisons were performed based
on dose-volume histogram (DVH) analysis including dosimetric parameters such as the homogeneity index
(HI), conformity index (CI), Dmax, Dmin, and Dmean for the planning treatment volume (PTV), in addition
to dose-volume parameters for the organs at risk (OARs). The delivery efficiency of the three types of MLCs
was compared in terms of the beam delivery time and the monitor units (MUs) per fraction for each plan.
Results Both target uniformity and conformity were improved in plans for Agility and BM MLC compared
with the plan using MLCi2. The mean HI decreased from 1.14 for MLCi2 to 1.13 for BM and 1.10 for Agility,
while the mean CI increased from 0.68 for MLCi2 to 0.73 for BM and 0.75 for Agility. Furthermore, at both
low and high dose levels, smaller volumes of ipsilateral lung, heart, contralateral lung, and breast were
irradiated with Agility MLC than with the other two types of MLCs. The delivery time with Agility MLC was
reduced by 10.8% and 32.1%, respectively, compared with that for MLCi2 and BM.
Conclusion Our results indicate that the Agility MLC exhibits a dosimetric advantage and a significant
improvement in delivery efficiency for the treatment of breast cancer using VMAT. |
| Close |
|
|
|