ABSTRACT
Changes in atmospheric pressure and temperature aect the radiation output because of the ion-chamber design of the CyberKnife System. e output of the linear accelerator needs to be checked or veried daily. Additional checks throughout the day may be required if dramatic environmental changes occur. It is recommended that no adjustment to the calibration factor be made if the variation is within a tolerance level of 2% (Dieterich et al.). However, if the variation exceeds this limit, a qualied medical physicist must change the calibration factor by following the steps in calibration adjustment provided by the CyberKnife System. Aerward, additional verication measurements are required.
