What methods of image guidance are available on your linac?
How often is this guidance performed?
For what treatment targets?
Methods of image guidance
My department has four linear accelerators. The old Linac 1 was replaced with a modern version. It could only perform portal films using radiographic film.
- The three very modern linacs are capable of performing on board imaging, either kilovoltage, megavoltage, or cone beam CT
- The older (but still modern) linac an inbuild electronic portal imaging device which is for MV portal imaging only
Use of image guidance
Image guidance is used for most radical cases, particularly prostate and head and neck treatments which require a high degree of accuracy. Palliative cases rarely need image guidance. Image guidance may be performed daily (head and neck, prostate) or weekly (breast).