4D CT imaging
An example of a four-dimensional (4D) CT scan, where the images are acquired along with the breathing signal to show the anatomy at different breathing phases.
Rotating x-ray images of a pancreas cancer patient with implanted markers acquired prior to treatment. The positions of the markers in each image can be used to compute the tumour trajectory. Courtesy Dr. Per Poulsen, Aarhus University, Denmark.
Rotating x-ray images of a prostate cancer patient acquired during a radiation treatment. The positions of the implanted markers were used to compute the tumour trajectory to within 1mm. In this case, 18mm of tumour motion was observed during treatment.
A demonstration of MLC tracking during large animal radiotherapy. The target position is measured by imaging a stent implanted into the pig lung. The position of the stent is used to guide the beam so that it follows the target during treatment. Courtesy Dr. Per Poulsen, Aarhus University, Denmark.
A demonstration of MLC adaptation to a rotating phantom target. The target position and rotation information was acquired using a Calypso system which was used to guide the beam so that it follows the target during treatment.
A demonstration of MLC adaptation to a deforming phantom target which simulates the relative motion between the tumour system. The target deformation information was acquired by deformable image registration of the intrafractional images to the planning image.
A series of coronal CT images (grayscale) of a lung cancer patient with the CT-measured ventilation information overlaid (colour). Red indicates high ventilation, blue indicates low ventilation. This information could be used for avoiding high-functioning lung during cancer radiotherapy. Courtesy Dr. Yamamoto, Stanford University.