Systematic set-up uncertainties
•
Same error in every fraction
•
Examples
➢
Incorrect reconstruction procedures
(source path commissioning)
➢
Systematic misinterpretation of images
CT
MR
Random set-up uncertainties
•
Different in every fraction
•
Visibility of applicator
(dependent on slice thickness)
•
Uncertainties of image fusion
•
Pronounced in longitudinal direction
(perpendicular to slice orientation)
Sagittal reconstruction
from para-transverse MR
Sagittal reconstruction
from transverse MR
© K. Tanderup
Hellebust et al
2007, PMB 52
Berger et al.
2009, R&O 93