2017_IGRT course book

The AHARA principle

Make patient cure As High As Reasonably Achievable Kill tumor and …. limit complications by precisely delivering the treatment Reduce secondary cancer by reducing the margin

Imaging (dose) is required to: Eliminate geometric miss  improve outcome Lower dose to adjacent organs at risk like rectum Smaller margins  lower integral dose

Imaging dose contributes a few % to organs that already receive a fairly high dose due to radiotherapy:  order of magnitude less important than having good treatment