I have a current patient under treatment and the shifts that we have seen are very minimal and the spine matches perfectly every day. I have had patients in the past where the mask would fit so snug with what one would think there would be no room for misplacement and after imaging the spine would be so different daily and it was do to the imperfect placement of the patients head on the headrest. The aquaplast masks have a certain amount of flexion to them to allow the head placement but the imperfection is clearly seen on imaging. With the Silverman AccuRest you can be rest assured that the patients head is perfectly aligned on the headrest as it was on the day of simulation and the spine will align perfectly as well. No more improper head tilt, no more spinal flexion and no more face mashing.