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Important for dose calculations
in small fields and IMRT.
Focal point
B-C is nearly
A-C
Positioning rounded collimator edges
38
A,BC
CB A
A: Projected tip
B: Tangent (light
field)
C: Half Value
Transmission
constant (approx.
0.3 mm) for a
Varian MLC.
A-B
Boyer and Li [6]
Utrecht 2016