We now use GateCT at simulation for all DIBH patients. As our AlignRT system went live prior to GateCT install we did sim a couple of patients without the system in CT. In these instances we used our old C-Rad Sentinel system which has similar functionality to GateCT.
VisionRT has initially advised us some centers in the UK using AlignRT did not purchase GateCT. In these centers it was standard practice to use CT lasers to draw lateral marks on the patient at free-breathing stage, encourage DIBH and to look for a vertical displacement of ~1.5cm (1cm minimum). There was no way to monitor stability of breath hold during the CT scan using this technique. We did not feel comfortable using this technique for this reason and continued to use C-Rad Sentinel until GateCT install.