Margin expansions of different regions of interest in craniospinal irradiation using helical tomotherapy(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2022年第11期
- Page:
- 1334-1338
- Research Field:
- 医学放射物理
- Publishing date:
Info
- Title:
- Margin expansions of different regions of interest in craniospinal irradiation using helical tomotherapy
- Author(s):
- ZHANG Wei; HUAN Fukui; ZHANG Yanxin; LI Tantan; LI Wei; HUANG Peng; HU Zhihui; QIN Shirui; MEN Kuo; LUO Jingwei
- Department of Radiation Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100021, China
- Keywords:
- Keywords: craniospinal irradiation helical tomotherapy setup error target volume margin expansion
- PACS:
- R811
- DOI:
- DOI:10.3969/j.issn.1005-202X.2022.11.003
- Abstract:
- Abstract: Objective To carry out image registration and setup error analysis with skull, cervical spine, thoracic vertebra, lumbar vertebra and the whole planning target volume (PTV) in MVCT images of patients treated by craniospinal radiotherapy using helical tomotherapy (TOMO) as regions of interest (SROI, CROI, TROI, LROI, PTVROI, respectively), and to calculate the margin expansion of each ROI. Methods A total of 154 sets of MVCT images of 16 patients who received craniospinal radiotherapy using TOMO in Cancer Hospital, Chinese Academy of Medical Sciences from 2016 to 2020 were analyzed retrospectively. The skull, cervical spine, thoracic spine, lumbar spine and planning target volume were registered separately. The setup errors of different regions were recorded, and 5 groups of setup errors including X (left-right), Y (superior-inferior) and Z (anterior-posterior) directional setup errors were obtained to analyze the difference among SROI, CROI, TROI, LROI and PTVROI, and the formula M=2.5Σ+0.7σ was applied to calculate the CTV-PTV margin of each ROI. Results The differences in X directional setup errors between any two groups were trivial, except for SROI vs CROI (P=0.023) and the Y directional setup erros in any two groups were close. The compassion of Z directional setup error showed that there were statistically significant differences in PTVROI vs CROI (P<0.001), PTVROI vs LROI (P<0.001), SROI vs CROI (P=0.007), SROI vs TROI (P=0.017), SROI vs LROI (P<0.001), CROI vs TROI (P<0.001), CROI vs LROI (P<0.001), TROI vs LROI (P<0.001), but not in PTVROI vs SROI, PTVROI vs TROI. Conclusion In craniospinal irradiation using TOMO, the difference in Y directional PTV margin expansion is insignificant, but the X and Z directional margin expansions show an increasing trend from head to lumbar spine. It is suggested that different PTV margin expansion strategies should be adopted at different craniospinal regions.
Last Update: 2022-11-25