Hybrid volumetric modulated arc therapy for whole breast irradiation: a dosimetric comparison of different arc designs
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To find an optimal arc design for hybrid volumetric modulated arc therapy (H-VMAT), a combination of conventional 3DCRT and VMAT plans for left-sided whole breast radiation therapy.
Methods and materials
A total of 26 left-sided early-stage breast cancer patients were selected for this study. To find the superior plan, H-VMAT with three different arc designs including, two partial arcs (2A), four partial arcs (4A) and four tangential arcs (TA) were created for each study case by combining 3DCRT and VMAT with 75% 3DCRT/25% VMAT dose proportion of prescription dose.
All H-VMAT plans achieved the expected target coverage. A higher conformity index and homogeneity index were achieved for 2A and 4A H-VMAT plans and significantly differ from TA H-VMAT (p < 0.003). The heart and ipsilateral lung dose parameters were comparable among all plans except heart V40Gy which was significantly less in 4A H-VMAT plan (p < 0.05). The contralateral lung, contralateral breast, spinal cord, normal tissue doses and MU were significantly less in TA H-VMAT (p < 0.03). The beam-on time was significantly less in 2A H-VMAT (p < 0.0001).
2A and 4A H-VMAT techniques are effective in improving the PTV dosimetric parameters as well as reducing the OAR doses. Further, 2A H-VMAT delivers less MU and beam-on time compared to 4A H-VMAT.
KeywordsBreast cancer Whole breast VMAT Hybrid-VMAT
Compliance with ethical standards
Conflict of interest
All authors who contributed to this study declare that they have no conflict of interest with respect to the manuscript.
Institutional scientific and ethics board has approved this study. This article does not contain any studies with human participants performed by any of the authors.
The informed consent has been waived off by the ethics board of the institute considering this as a retrospective study with no human involved. For this type of study, formal consent is not required.
- 2.Early Breast Cancer Trialists’ Collaborative Group (EBCTCG) (2005) Effect of radiotherapy after breast-conserving surgery on 10-year recurrence and 15-year breast cancer death: meta-analysis of individual patient data for 10801 women in 17 randomized trials. Lancet 365:1687–1717CrossRefGoogle Scholar
- 21.Chen YG, Li AC, Li WY et al (2017) The feasibility study of a hybrid coplanar arc technique versus hybrid intensity-modulated radiotherapy in treatment of early-stage left-sided breast cancer with simultaneous-integrated boost. J Med Phys 42(1):1–8. https://doi.org/10.4103/jmp.JMP_56_17 CrossRefGoogle Scholar
- 22.Lin J, Yeh D, Yeh H et al (2015) Dosimetric comparison of hybrid volumetric-modulated arc therapy, volumetric-modulated arc therapy and intensity-modulated radiation therapy for left-sided early breast cancer. Med Dosim 40(3):262–267. https://doi.org/10.1016/j.meddos.2015.05.003 CrossRefGoogle Scholar
- 31.International Commission on Radiation Units and Measurements (2010) ICRU report 83: prescribing recording and reporting photon beam intensity modulated radiation therapy (IMRT). ICRU Rep 10(1):1–92Google Scholar
- 38.Kinoshita R, Shimizu S, Taguchi H et al (2008) Three-dimensional intrafractional motion of breast during tangential breast irradiation monitored with high-sampling frequency using a real-time tumor-tracking radiotherapy system. Int J Radiat Oncol Biol Phys 70(3):931–934. https://doi.org/10.1016/j.ijrobp.2007.10.003 CrossRefGoogle Scholar