Methods for delivering radiation dose to a target area within a subject comprise: defining a trajectory comprising relative movement between a treatment radiation source and the subject and determining a radiation delivery plan； and, while effecting relative movement between the treatment radiation source and the subject along the trajectory, delivering a treatment radiation beam from the treatment radiation source to the subject according to the radiation delivery plan to impart a dose distribution on the subject. Delivering the treatment radiation beam from the treatment radiation source to the subject comprises varying an intensity of the treatment radiation beam over at least a portion of the trajectory. Varying the intensity of the treatment radiation beam comprises varying a radiation output rate of the treatment radiation source in accordance with the radiation delivery plan while effecting relative movement between the treatment radiation source and the subject along the trajectory.
