IEC 60601-2-64:2014 applies to the basic safety and essential performance of Light Ion Beam Medical Electrical equipment, hereafter referred to as ME equipment, used for treatment of patients. This particular standard, with the inclusion of type tests and site tests, applies respectively to the manufacture and some installation aspects of ME equipment intended for radiotherapy in human medical practice, including those in which the selection and display of operating parameters can be controlled automatically by programmable electronic subsystems, that, in normal use, deliver a radiation beam of light ions having energy per nucleon in the range 10 MeV/n to 500 MeV/n. Key words: nuclear medicine, radiation dosimetry.