2017_IGRT course book

Reliability of bony anatomy

Set-up prior to treatment was verified based on the a) position of the metastasis (soft tissue match): imaging using an in-room CT scanner after application of iv contrast b) position of the bony anatomy (bone match): imaging using cone-beam CT However, internal “motion” of intra-cerebral tumor could be caused by: • Tumor progression • Tumor shrinkage • Changes of peritumoral edema If visualization of the target is not possible, one has to use the bony skull as a surrogate for the actual intra-cranial target in IGRT

a

b