Apparatus and method for evaluating an activity distribution, and irradiation system

Apparatus for evaluating a particle beam deposited dose distribution in a moved target object comprising:

• the particle beam for irradiating the moved target object thereby inducing an activity distribution which generates photons in the moved target object,
• a position emission tomograph designed to record the photons generated in the target object by the particle beam and configured to generate measurement data representing points of origin of the photons,
• a movement detection device designed to generate a movement signal representing the movement of the target object, and
• an evaluation unit designed to generate a movement signal representing the movement of the target object, and
• an evaluation unit designed to correlate the points of origin of the measurement photons with positions in the target object using the movement signal in such a way that three dimensional characteristics of the activity distribution actually generated in the target object by the particle beam can be evaluated by means of the photons generated by the beam,
• wherein the evaluation unit is also configured to determine from an intensity of the measured photons a quantitative measure for temporally and/or locally successively deposited single doses at the positions in the target object, and
• wherein the evaluation unit is also configured to determine from the temporally and/or locally successively deposited single doses in a temporally protracted irradiation the particle beam deposited dose distribution in the target object to provide information as to how irradiation can be optimized.