Figure 3From: Geographic miss of lung tumours due to respiratory motion: a comparison of 3D vs 4D PET/CT defined target volumesCT scan of a patient with a small lower lobe tumour. The 4D-GTV is shown in red and the 3D-PTV is shown in green. The highlighted red area is the part of the 4D-GTV that was not covered by the 3D-PTV for the margin applied.Back to article page