A phantom for evaluating nondosimetric functions in radiation therapy installation
having a patient couch and a gantry with a head thereon for generating a multi-leaf
collimated beam, wherein the beam is directed toward the couch at an orientation
dictated by relative orientations of the couch and gantry. The phantom comprises
a base adapted for disposition on the couch, and a component mounted to the base
for rotation in accordance with the relative orientations of the couch and gantry.
The component incorporates a plurality of known geometrical structures corresponding
in shape to the multi-leaf collimated beam. Upon imaging the component, nondosimetric
functions may be evaluated by comparing the known geometrical structures with images
of the structures and identifying discrepancies therebetween.
