2017_IGRT course book

EPIDs: Pros and cons

Isocentric alignment: the imaging beam is the treatment beam (obs: gravity)

Monoscopic: needs several angles for 3D positioning information

Considerable dose for large FOV images outside the target volume (1 to 5 MU per image)

The imaging dose to the patient can be easily calculated in the TPS

Low contrast (bony structures or markers)

Verifies the field outline with respect to the patient anatomy

Can use the EPID for transmission (in vivo) dosimetry