In various embodiments, methods and devices are provided for generating a radiotherapy treatment plan for a subject to be implemented on a radiotherapy device. In certain embodiments the methods involve determining all feasible radiotherapy beam orientations free of collision for said radiotherapy device and said subject to provide a set of radiotherapy beam orientations； selecting from the set of all feasible radiotherapy beam orientations a subset of beams that meet treatment goals to be used in treatment of the subject to provide a selected beam set； calculating a navigation trajectory for the radiotherapy device to delivery said subset of beams to the subject where the trajectory is free of collision； and generating and writing instruction files to a tangible medium that can be executed by said radiotherapy device.
