An improved particle beam treatment system optionally includes exchangeable particle beam nozzles. These particle beam nozzles may be automatically moved from a storage location to a particle beam path or between particle beam paths for use in medical applications. Movement may be achieved using a conveyance, gantry, rail system, or the like. The improved particle beam treatment system optionally also includes more than two alternative particle beam paths. These alternative particle beam paths may be directed to a patient from a variety of different angles and in different planes.