Effects of CT contrast agent on dose calculations for volumetric modulated arc therapy of brain arteriovenous malformations(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2021年第5期
- Page:
- 556-560
- Research Field:
- 医学放射物理
- Publishing date:
Info
- Title:
- Effects of CT contrast agent on dose calculations for volumetric modulated arc therapy of brain arteriovenous malformations
- Author(s):
- DENG Guanhua; LI Shaoqun; ZHOU Qiaomin; LUO Rishun; ZHANG Ping; DAI Peng; LUO Longhui; LAI Mingyao; SHAN Changguo; CAI Linbo
- Department of Oncology, Guangdong Sanjiu Brain Hospital, Guangzhou 510510, China
- Keywords:
- Keywords: brain arteriovenous malformation volumetric modulated arc therapy CT contrast agent dose calculation
- PACS:
- R739.41；R815.6
- DOI:
- DOI:10.3969/j.issn.1005-202X.2021.05.006
- Abstract:
- Abstract: Objective To investigate the effects of CT contrast agent on the dose calculations for volumetric modulated arc therapy (VMAT) of brain arteriovenous malformations. Methods Fifteen patients with brain arteriovenous malformations were enrolled in the study and underwent contrast enhanced CT (CECT) scan and non-enhanced CT (NECT) scan in the same position. Target areas and organs-at-risk were delineated on CECT image, and then copied to NECT image after image registration. VARIAN Eclipse planning system 13.6 was used to generate VMAT plan with 5 arcs based on CECT, and the generated plan was copied to NECT for recalculating dose distributions, without flux optimization. The Hounsfield unit (HU) of planning target volume, organs-at-risk and region of interest, the D2%, D98%, Dmean, conformity index, homogeneity index and gradient index of planning target volume, the Dmax of organs-at-risk, and the V2 Gy, V10 Gy and V12 Gy of normal tissues were recorded and analyzed. A Wilcoxon signed rank test was conducted to compare the differences between two groups of data. Results The HU of planning target volume and region of interest in CECT were higher than those in NECT (P=0.001), and there was no significant difference in HU of other tissues (P>0.05). The differences in dosimetric parameters between two groups were less than 2%, without significant differences (P>0.05). Conclusion The effect of CT contrast agent on the dose calculation for VMAT of brain arteriovenous malformations is ignorable.
Last Update: 2021-05-31