Basic Treatment Planning

Contrast and Artefacts • IV contrast may be used during CT for head and neck patients. This must be accounted for when planning. • Create a volume which covers any contrast in and around the treatment area. • Remove areas of bone, lung, airways from this. • Give unit density of 1 to the contrast in this region • If necessary, use a similar technique to remove artefact caused by dental filling or other high density regions, eg shunts