ASMR 2017

At the start of treatment

• Single CT introduces systematic errors*:



Delineation errors



Organ position and shape at time of localization



Phantom transfer errors o Geometric imaging error o

Treatment planning system error Linear accelerator geometry error Set-up error at time of localization

o

o



TPS beam algorithm error Breathing positional error



*McKenzie et al., BIR 2003 Image courtesy: Marcel van Herk