An example method of treating a target using particle beam includes directing the particle beam along a path at least part-way through the target, and controlling an energy of the particle beam while the particle beam is directed along the path so that the particle beam treats at least interior portions of the target that are located along the path. While the particle beam is directed along the path, the particle beam delivers a dose of radiation to the target that exceeds one (1) Gray-per-second for a duration of less than five (5) seconds. A treatment plan may be generated to perform the method.