Advanced Physics for Brachytherapy 2018

Systematic set-up uncertainties

Berger et al. 2009, R&O 93

•

Same error in every fraction

•

Examples

➢

Incorrect reconstruction procedures (source path commissioning)

CT

MR

Hellebust et al 2007, PMB 52

➢

Systematic misinterpretation of images

Random set-up uncertainties

Sagittal reconstruction from para-transverse MR

Sagittal reconstruction from transverse MR

• •

Different in every fraction Visibility of applicator (dependent on slice thickness) Uncertainties of image fusion Pronounced in longitudinal direction (perpendicular to slice orientation)

• •

© K. Tanderup