Dosimetric study on improved non-coplanar volumetric modulated arc therapy for hippocampal avoidance whole-brain radiotherapy(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2021年第5期
- Page:
- 529-533
- Research Field:
- 医学放射物理
- Publishing date:
Info
- Title:
- Dosimetric study on improved non-coplanar volumetric modulated arc therapy for hippocampal avoidance whole-brain radiotherapy
- Author(s):
- YU Xiao; YAN Bing; LIU Lei; LI Xiaoyang; SHEN Jianjun; WU Aidong
- Department of Radiation Oncology, the First Affiliated Hospital of University of Science and Technology of China, Hefei 230001, China
- Keywords:
- hippocampus whole-brain radiotherapy volumetric modulated arc therapy non-coplanar coplanar
- PACS:
- R811.1；R815.6
- DOI:
- DOI:10.3969/j.issn.1005-202X.2021.05.001
- Abstract:
- Objective To improve the non-coplanar volumetric modulated arc therapy (VMAT) for hippocampal avoidance whole-brain radiotherapy (HA-WBRT), and to compare dosimetric differences among improved non-coplanar VMAT, non-coplanar VMAT and coplanar VMAT for HA-WBRT. Methods Fifteen patients scheduled for WBRT for brain metastasis from extracranial tumors were enrolled in the study, and 3 different kinds of plans, namely improved non-coplanar VMAT, non-coplanar VMAT and coplanar VMAT plans, were designed for each patient. The doses delivered to target areas and organs-at-risk, monitor unit and treatment time were compared among 3 different kinds of plans. Results There were no statistical differences among 3 different kinds of plans in conformity index and gradient index (P>0.05), but improved non-coplanar VMAT plan had a higher homogeneity index than the other two kinds of plans. The Dmax, Dmin and Dmean of hippocampus in improved non-coplanar VMAT plans could be limited to 14.37, 8.40 and 10.80 Gy, respectively, which were significantly lower than those in non-coplanar VMAT plans and coplanar plans (P<0.05). The doses delivered to other organs-at-risk, such as lens and optic nerves, were within the range of clinical safe dose, and no statistical significance was found among different plans. The monitor unit and treatment time of improved non-coplanar VMAT plans were both greater than those of non-coplanar VMAT plans and coplanar VMAT plans, with statistical differences (P<0.05). Conclusion Compared with non-coplanar VMAT and coplanar VMAT, improved non-coplanar VMAT for HA-WBRT can further reduce the dose delivered to hippocampus, providing a practicable treatment strategy for the clinical application of HA-WBRT.
Last Update: 2021-05-31