127 / 1359
Important for dose calculations
in small fields and IMRT.
A,BC
CB A
A: Projected tip
B: Tangent (light
field)
C: Half Value
Transmission
Focal point
B-C is nearly
constant (approx.
0.3 mm) for a
Varian MLC.
A-C
A-B
Boyer and Li [6]
Positioning rounded collimator edges
Dublin 2018