741 / 1542
Patient motion
BEV of MLC
accounts for
beam divergence
in lateral direction
Helical Tomotherapy - binary MLC
•
leaves 95% tungsten, thickness 10 cm
•
leaf width projected at isocenter: 0.625 cm
•
y-jaws collimate the beam to 1.0, 2.5 or 5.0 cm at isocenter
•
leaves are either fully closed or fully opened, when closed: stop
under opposite y-jaw
•
IMRT: treat with optimized leaf specific opening times