ASMR

3D (CBCT)

• Limitations  Collision 

Field of view

Increased dose to contra lateral breast



• CBCT not acquired at the isocentre to avoid collision • Then once matched the shift includes the offset from isocentre position • Adds time and potential errors • Donovan et al. (2012) stipulate limitations on iso position to account for this • Half bowtie filter (Varian OBI) increases FOV in longitudinal direction