An example particle therapy system includes the following: a gantry that is rotatable relative to a patient position； a particle accelerator mounted to the gantry, where the particle accelerator is for outputting a particle beam essentially directly to the patient position； and a control system to receive a prescription and to generate machine instructions for configuring one or more operational characteristics of the particle therapy system. At least one of the operational characteristics relates to a rotational angle of the gantry relative to the patient position.
