Stereotactic radiosurgery for large brain metastases: a dosimetric comparison of volumetric modulated arc therapy generated with RapidArc versus HybridArc(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2019年第8期
- Page:
- 887-891
- Research Field:
- 医学放射物理
- Publishing date:
Info
- Title:
- Stereotactic radiosurgery for large brain metastases: a dosimetric comparison of volumetric modulated arc therapy generated with RapidArc versus HybridArc
- Author(s):
- ZHANG Ping1; DENG Guanhua1; DAI Peng1; LUO Longhui1; HUANG Qing1; CAI Linbo1; WANG Jun2
- 1. Department of Oncology, Guangdong Sanjiu Brain Hospital, Guangzhou 510510, China; 2. Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
- Keywords:
- ; Keywords: large brain metastases; stereotactic radiosurgery; HybridArc; RapidArc; dosimetric comparison
- PACS:
- R815.6；R312
- DOI:
- DOI:10.3969/j.issn.1005-202X.2019.08.005
- Abstract:
- Abstract: Objective To explore the effects of HybridArc and Rapidarc on the dosimetric parameters and machine units of stereotactic radiosurgery plans for large brain metastases. Methods Ten patients with large brain metastases were enrolled in this study. Different techniques, namely RapidArc and HybridArc, were used to design two kinds of treatment plans for each patient. The conformity index (CI), gradient index (GI), homogeneity index (HI) of target areas, the dose distributions of organs-at-risk, the doses to normal tissues and machine units between RapidArc plan and HybridArc plan were compared. Results The HI of target areas was similar in RapidArc plan and HybridArc plan, without statistical difference (t=-1.400, P=0.161); the CI of target areas in RapidArc plan was closer to 1, while the GI of target areas in HybridArc plan was closer to 1, with statistical differences (CI: t=-2.521, P=0.012; GI: t=-2.240, P=0.025). Compared with RapidArc plan, HybridArc plan had reduced 2 Gy isodose volume, with statistical difference (P=0.012) and increased 16 and 20 Gy isodose volumes, with statistical difference (P=0.012, 0.017). No significant difference was found between RapidArc plan and HybridArc plan in 4, 6, 8 and 12 Gy isodose volumes (P=0.575, 0.050, 0.069, 0.068). The maximum dose of brainstem, right eye, left optic nerve and right optic nerve in HybridArc plan were lower than those in RapidArc plan, with statistical differences (P=0.012, 0.017, 0.017, 0.017), but the maximum dose of bilateral lens, left eye and chiasm were similar in the two kinds of plans (P[≥]0.05). Compared with that of RapidArc plan, the machine units of HybridArc plan was reduced by 908 MU. Conclusion Using HybridArc to design stereotactic radiosurgery for large brain metastases provided better target conformity and GI, less machine monitor units, higher dose in high-dose area of normal tissues and lower maximum dose of some organs-at-risk.
Last Update: 2019-08-26