| 摘要 |
Apparatus and method in the field of x-ray therapy used for radiation treatment of an intercranial portion of a patient. The present apparatus and method are used to solve the problems of geometrical imprecision due to sagging and impractical dose rates when a small collimator is used. These problems are solved in the present device which comprises a linear accelerator for supplying energetic electrons to a collimator (14) which supplies x-rays to a region (F1). The collimator (14) includes a plurality of channels (26) oriented toward the region (F1). Each channel (26) has a target (32) which produces x-ray radiation when the respective target (26) is selectively exposed to the electrons. The collimator (14) has a cover layer of radiation attenuation material (54), which extends over the outer surface of collimator (14) leaving the channels (26) exposed to the electrons. Preferably, the cover layer (54) has a thickness at least equal to the range of the energetic electrons. |
