An apparatus includes a plurality of detection pixels configured to generate a signal according to a radiation irradiation amount to obtain radiation irradiation information, a detection unit configured to correspond to a region of the plurality of detection pixels and detect one of light, pressure, capacitance, and temperature as two-dimensional information, and a control unit configured to determine a monitoring target detection pixel and a non-monitoring-target detection pixel among the plurality of detection pixels based on the two-dimensional information detected by the detection unit, read the signals of detection pixels of a row in which the monitoring target detection pixel is included.
