Figure 1From: An EPID-based method for comprehensive verification of gantry, EPID and the MLC carriage positional accuracy in Varian linacs during arc treatmentsA sample image acquired for characterization of Varian linac components at SDD = 150 cm. The shadows of the markers attached to the head are labelled as (a), (b), (c) and (d). The ball bearing at the isocentre is named (e). The X and Y directions represent the cross-plane and in-plane directions, respectively.Back to article page