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Metaphysics margins?
•
Clinically used margin for breast:
0 mm!
– Adapted from sim-technique - it’s just beam setup
– Clearly not enough according to conventional margin ideas
•
Clinically used margin for boost: 5 mm
– Let’s see if that’s enough
– Margin: 2.5 * 3.2 + 0.3 * 3.2 =
9 mm
Systematic
Random
Delineation
2.0 mm
-
Setup
1.5 mm
2.5 mm
Shape changes 2.0 mm
2.0 mm
Total
3.2 mm
3.2 mm
Because of
background dose