ESTRO course Dose Modelling and Verification 2017

45

Wedge induced beam quality shifts

Physical wedges filter the beam, yielding beam hardening. Although, above approx. 15 MV the pair production process will balance the hardening, resulting in unaffected (or even softer) beam quality.

Zhu et al [9]

Knöös and Wittgren [16]

PW60=60 deg Physical wedge VW60=60 deg Virtual wedge

T Knöös

Warsaw 2017