System (100) for assembling a strand of radioactive seeds, comprising: a housing (101) having a plurality of receptacles (104) each being configured to receive a cartridge； a plurality of cartridges (106), each of said cartridges being configured to be received within one of said receptacles, containing at least one of said radioactive seed cartridges, containing at least one of said non-radioactive connector cartridges, and containing at least one of said non-radioactive spacer cartridges； wherein each cartridge (106) may contain one of radioactive seeds, non-radioactive connectors and non-radioactive spacers； a slide selector (103) that can be operated to select one of said cartridges； a rail (112) configured to receive a plurality of said radioactive seeds, non-radioactive connectors and non-radioactive spacers； an actuator (108) configured to eject one of a seed, a non-radioactive connector and a spacer from said selected cartridge to said lane； and a slider combiner (110) with respect to the housing, the combiner being able to be operated to combine a plurality of seeds, connectors and spacers in a single strand, and in which each receptacle has a different shape, whereby only one of the plurality of cartridges (106) will fit in any receptacle.Sistema (100) para ensamblar una hebra de semillas radiactivas, que comprende: un alojamiento (101) que tiene una pluralidad de receptáculos (104) estando configurado cada uno para recibir un cartucho； una pluralidad de cartuchos (106), estando configurado cada uno de dichos cartuchos para ser recibido dentro de uno de dichos receptáculos, conteniendo al menos uno de dichos cartuchos semillas radiactivas, conteniendo al menos uno de dichos cartuchos conectores no radiactivos, y conteniendo al menos uno de dichos cartuchos espaciadores no radiactivos； en el que cada cartucho (106) puede contener uno de semillas radiactivas, conectores no radiactivos y espaciadores no radiactivos； un selector (103) deslizable que puede acci
