Framebased-Frameless_DV_2017

The “shift” part: systematic

•

Systematic uncertainties (typically preparation errors) cause a

shift

of the (blurred) dose distribution.

•

Again, we assume the systematic uncertainties within a certain

population of patients to be described by a normal distribution

SBRT 2017 - D. Verellen

Average uncertainty per patient: systematic

SD per patient: random, σ

SD of all systematic uncertainties: Σ

sys

to ensure that for 90% of all

systematic errors, the CTV

receives 95% of the prescription dose