SBRT2015

Patient specific pre-treatment QA • Verifying if marker motion is appropriate surrogate of tumour motion

Surrogate value: COM Single Visicoil marker vs. COM GTV

Max deviation 1.2 mm in CC (CT slice 2 mm)

Ex. 1

LAT

AP

CC

(x,y,z) COM , Visicoil =(x,y,z) COM,GTV +Cte

For large amplitudes (> 15 mm p2p):

Ex. 2

Stable

Artefact

LAT

AP

CC

Exhale

Mid. Vent.

4D CT Artefacts

42

SBRT 2015 - D. Verellen