| 摘要 |
<p>A method of aligning the radiation beam in a radiotherapy system comprising a source for producing a beam of radiation and a device for imaging from the beam, both mounted so as to be rotatable about an axis using a fiducial phantom between the source and the device, the method comprising: rotating the beam and device in a trajectory about the axis while obtaining a plurality of images of the fiducial phantom from a plurality of different angles, determining from each image of the fiducial phantom the position of the source at the rotational position the image was obtained, and calculating the centre of rotation of the positions of the source to define the isocentre of the system. The invention enables the alignment of a collimator with the source of radiation, the reduction of asymmetry in beam intensity, and is also applicable to magnetic resonance-guided radiotherapy.</p> |
