Imaging for Physicists

Different methods for tumor delineation on PET produce very different results

FDG-PET

CT

• GTV 40 : • GTVbg: • GTV CT :

take 40% of SUV max

as threshold

threshold based on mean within GTV 70

and background

delineation on CT

• GTV 40

is inadequate, but GTV bg

also differs significantly from GTV CT

Nestle et al. 2005; J. Nucl. Med. 46:1342-1348