An irradiation apparatus comprising a device for evaluating an activity distribution occurring in a moved target object, wherein the irradiation apparatus comprises an irradiation device adapted to generate a beam, and wherein said activity distribution can be produced by the beam generated by said irradiation device; wherein the irradiation device includes a second control unit and wherein said second control unit is adapted to control a course of irradiation by the beam; wherein said device for evaluating comprises: a positron emission tomography device adapted to record photons generated in the target object by said beam and to generate measurement data representing points of origin of the photons, comprising a first control unit; - a movement capturing device adapted to generate a movement signal which represents the movement of the target object; a data acquisition unit for controlling the data acquisition of the positron emission tomography device, comprising ∘ a first input for acquiring the measurement data of the positron emission tomography device; ∘ a second input for inputting, into the data acquisition unit, data related to the beam characteristics; ∘ a third input which is connected to the second control unit of the irradiation device, for inputting, into the data acquisition unit, beam parameters used to control the particle beam; ∘ a fourth input for acquiring the movement signal generated by the movement capturing device; wherein said data acquisition unit is further adapted to store the signals and measurement data acquired at the inputs in time-correlated manner; - an evaluation unit adapted to associate the points of origin of the measured photons with positions in the target object using the movement signal, whereby, through the photons generated by the beam, a spatial characteristic of the activity distribution actually generated in the target object can be evaluated in time-resolved and movement-corrected manner; - wherein the controlling of the course of irradiation by the second control unit simultaneously causes the data acquisition unit to control the data acquisition by the positron emission tomography device, so that the time-resolved and movement-corrected activity distribution determined by the evaluation unit can be related to the course of irradiation. a positron emission tomography device adapted to record photons generated in the target object by said beam and to generate measurement data representing points of origin of the photons, comprising a first control unit; - a movement capturing device adapted to generate a movement signal which represents the movement of the target object; a data acquisition unit for controlling the data acquisition of the positron emission tomography device, comprising ∘ a first input for acquiring the measurement data of the positron emission tomography device; ∘ a second input for inputting, into the data acquisition unit, data related to the beam characteristics; ∘ a third input which is connected to the second control unit of the irradiation device, for inputting, into the data acquisition unit, beam parameters used to control the particle beam; ∘ a fourth input for acquiring the movement signal generated by the movement capturing device; wherein said data acquisition unit is further adapted to store the signals and measurement data acquired at the inputs in time-correlated manner; ∘ a first input for acquiring the measurement data of the positron emission tomography device; ∘ a second input for inputting, into the data acquisition unit, data related to the beam characteristics; ∘ a third input which is connected to the second control unit of the irradiation device, for inputting, into the data acquisition unit, beam parameters used to control the particle beam; ∘ a fourth input for acquiring the movement signal generated by the movement capturing device; - an evaluation unit adapted to associate the points of origin of the measured photons with positions in the target object using the movement signal, whereby, through the photons generated by the beam, a spatial characteristic of the activity distribution actually generated in the target object can be evaluated in time-resolved and movement-corrected manner; - wherein the controlling of the course of irradiation by the second control unit simultaneously causes the data acquisition unit to control the data acquisition by the positron emission tomography device, so that the time-resolved and movement-corrected activity distribution determined by the evaluation unit can be related to the course of irradiation.