Physics Bucharest 2017

accounts for beam divergence in lateral direction

Helical Tomotherapy - binary MLC

BEV of MLC

• leaves 95% tungsten, thickness 10 cm • leaf width projected at isocenter: 0.625 cm

Patient motion • 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