IGRT 2016 Madrid

Reliability of bony anatomy

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 However, internal “motion” of intra-cerebral tumor could be caused by: • Tumor progression • Tumor shrinkage • Changes of peritumoral edema 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

a

b