| 摘要 |
The invention relates to a collimator ( 1 ) for defining a beam of energetic rays ( 2 ) which is emitted from an essentially punctiform radiation source ( 3 ) and is oriented onto an object ( 1 ) to be treated. The collimator is especially used for the stereotactic conformation radiotherapy of tumors. The collimator ( 1 ) is embodied in such a way that an irregular object ( 4 ) can be scanned by rays ( 2, 2 ') which are defined by an opening in the collimator. The invention also relates to a program for controlling the collimator. In order to define the contours ( 29, 29', 29 '') of the objects ( 4 ) to be irradiated in a simple but highly accurate manner, especially with a precise definition of the irradiation fields, the collimator comprises a plurality of different sized openings ( 5, 5' 5 ''). One of the openings ( 5, 5', 5 '') can be selectively displaced in a polydirectional manner on a strip ( 6 ) having a spherical surface, and the central axis ( 7 ) thereof is oriented towards the radiation source ( 3 ). The other collimator openings ( 5', 5 '') are shielded form the rays ( 2 ). A control system ( 9 ) acts on the drives ( 23, 24, 25 ) of a drive device ( 8 ) in such a way that large openings ( 5, 5 ') are used to scan large irradiation surfaces ( 26 ) of the object to be treated ( 4 ), and small openings ( 5', 5 '') are used for precise definition at the edge of the irradiation surfaces ( 26 ) of the object to be treated ( 4 ), especially in the event of irregular contours ( 29, 29', 29 '').
|
