IGRT 2016 Madrid

EPIDs: Pros and cons

Isocentric alignment: the imaging beam is the treatment beam (obs: gravity) The imaging dose to the patient can be easily calculated in the TPS Verifies the field outline with respect to the patient anatomy Can use the EPID for transmission (in vivo) dosimetry

Monoscopic: needs several angles for 3D positioning information Considerable dose for large FOV images outside the target volume (1 to 5 MU per image) Low contrast (bony structures or markers)