Fig. 1.
Patient 2 treated in deep inspiration breath-hold: a) example of cone-beam CT imaging at linac (framed in yellow) overlaid with planning CT, showing also the planning target volume (PTV) contour (red) and the electromagnetic transponder (EMT) (pink), b) EMT centroid positions during session 8. The shaded grey area show the moments when the treatment beam was ON. The red horizontal lines indicate the ±3 mm tolerance threshold for beam gating. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)