

Impact of anatomical/positional changes
Increased used of image guidance
→
increased information
about current anatomy & position vs. plan.
Image comparison allows us to make subjective judgements
about e.g:
consistency of setup
effectiveness of immobilisation
external shape changes
internal anatomical changes
What we REALLY want to know is impact on dose delivered.
At what point are changes clinically significant? When is
action required?
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