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UMBRELLA Protocol – RT
Target Volume Definition
•
ITV: based on the observations of clip motion
with 4D-CT-imaging
•
PTV: includes ITV with 5-10 mm margin to
account for movement and set-up variability
•
PTV margin depends on IGRT frequency and
immobilization. Daily online position
verification is recommended if kV imaging
techniques are available. In this case CTV to
PTV expansion may be reduced to 5 mm