| 摘要 |
<p>The irradiation unit for ionising radiation, esp. for use in radiation therapy, comprises a radiation source and appts. for guiding the narrowly focused beam over the field to be irradiated. In the peripheral region of the field to be irradiated, the applied dose per element of area is increased by a control unit (16) connected to the irradiation unit (1), in order to compensate the reduction in total dose received in this peripheral region. If the applied dose per element of area is uniform over the entire field to be irradiated, the result is a weakening in total dose around the edge, due to the fact that lateral secondary irradiation from adjacent areas in this peripheral strip is considerably reduced by comparison with the more central parts of the field. By compensating with an increased applied dose, the total received dose is made more uniform across the entire field. The irradiation unit (1) comprises a detector (6) which measures the applied dose in each region, while the control unit (16) does not move on from one element of area to the next until the desired applied dose in each element has been reached. Mechanical two-dimensional pivoting of the radiation source (2) is pref. used to direct the beam (5).</p> |
