A process is provided for sterilizing brachytherapy devices with Ethylene Oxide gas and releasing the devices on a parametric release basis. Devices that can be sterilized with this process include interstitial radiation seed strand implants and the needles used for implantation. In order to be sterilized effectively by EtO gas, the devices are constructed such that surfaces not readily infused with EtO gas are made to be gas permeable, and will not retain the gas after the sterilization process. Performance qualification of the sterilization process is performed through physical and microbiological studies, and set of established physical process parameters. Maintaining the physical process parameters in subsequent sterilization cycles will consistently yield the desired sterility assurance level without having to test the devices for sterility.