Potential radiotherapy improvements with respiratory gating


DOI: 10.1007/BF03178368

Cite this article as:
Keall, P.J., Kini, V.R., Vedam, S.S. et al. Australas. Phys. Eng. Sci. Med. (2002) 25: 1. doi:10.1007/BF03178368


Gating is a relatively new and potentially useful therapeutic addition to external beam radiotherapy applied to regions affected by intra-fraction motion. The impact was of gating on treatment margins, image artifacts, and volume and positional accuracy was investigated by CT imaging of sinusoidally moving spheres. The motion of the spheres simulates target motion. During the CT imaging of dynamically moving spheres, gating reproduced the static volume to within 1%, whereas errors of over 20% were observed where gating was not used. Using a theoretical analysis of margins, gating alone or in combination with an electronic portal imaging device may allow a 2–11 mm reduction in the CTV to PTV margin, and thus less healthy tissue need be irradiated. Gating may allow a reduction of treatment margins, an improvement in image quality, and an improvement in positional and volumetric accuracy of the gross tumor volume.

Key words

respiratory gating margins image artifacts 

Copyright information

© Australasian College of Physical Scientists and Engineers in Medicine 2002

Authors and Affiliations

  • P. J. Keall
    • 1
  • V. R. Kini
    • 1
  • S. S. Vedam
    • 2
  • R. Mohan
    • 1
  1. 1.Department of Radiation OncologyVirginia Commonwealth University Health SystemRichmondUSA
  2. 2.Departments of Biomedical Engineering and Radiation OncologyVirginia Commonwealth University Health SystemUSA

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