Measuring device for checking radiation fields from treatment machines for radiotherapy

A measuring device for checking of radiation fields from treatment machines for radiotherapy, comprising a measuring block (11) containing radiation detector means (1-10) arranged under a cover plate (13) provided with field marking lines (14) and energy filter means (16), said detector means being connected to readout means for signal processing and presentation of measurement values, characterised in that said radiation detector means comprising:

• total dose detector means (1) centrally located in the measuring block (11) for checking dose monitor calibration, homogeneity detector means (2-5) located between the central detector means (1) and the edges of the measuring block (11) for determination of the beam homogeneity by comparing the reading thereof with those of the total dose detector means (1),
• edge detector means (6-9) for determination of the geometrical correspondence between the radiation field and the light field for setup of the radiation field by comparison of the readings thereof with those of the total dose detector means (1), and
• energy detector means (10) arranged below said energy filter means (16) for determination of the beam energy by comparison of the readings thereof with those of the total dose detector means (1),
• the arrangement of the radiation detectors (1-10) in the block (11) and the signal processing in the readout means being such that the dose monitor calibration, the homogeneity of the radiation field, the geometrical correspondence of the radiation field and the light field, and the energy of the radiation of the treatment machine can be checked simultaneously in one single irradiation of the measuring block (11) and subsequent reading of the measurement results.