Some aspects include a system, apparatus, means and method for configuring a radiotherapy beam shaping device to define a treatment field of view, acquiring images of a patient area within the treatment field of view based on an imaging radiation beam, determining a treatment motion model that predicts, based on the acquired images, a prediction treatment period during which the patient area will be within the treatment field of view of the radiotherapy beam shaping device, and delivering a treatment radiation beam to the patient area for a time period equal to the prediction treatment period.