Fig. 2.

[Setup correction vector and imaging time]. For surface scanning the time includes any following surface scans, couch movement, repositioning of the patient and megavoltage computed tomography (MVCT) imaging up till beam on. MVCT was performed for first three fractions and weekly if no relevant anatomical deviation was found and if the difference between MVCT and surface scanning was < 2 mm in any direction. The definition of the total setup correction vector (bottom) is here visualized as a sum of the individual correction vectors