A radiation irradiation system comprises a radiation irradiation device and a therapeutic bed (300) for transporting a target to be irradiated to the radiation irradiation device for irradiation. The therapeutic bed (300) comprises a positioning component (52). The positioning component (52) comprises a shielding body (54) and a sealing bag (53) for accommodating the shielding body (54). The shielding body (54) comprises silicone and a radiation shielding material which is capable of shielding a radiation. When the positioning component (52) with the target to be irradiated being placed on the surface of the sealing bag (53) is vacuumized, the positioning component (52) is recessed with the shape of the target to be irradiated at the position where the target to be irradiated is placed to form the same contour as the target to be irradiated, so as to position the target to be irradiated. The positioning component (52) is provided to position the target to be irradiated to avoid therapeutic effect differences caused by movement of the target to be irradiated during an irradiation therapy process, and avoid radioactive damages of radiation to parts of the target to be irradiated except for the parts on which irradiation therapy needs to be performed, and to medical staffs during the radiation irradiation therapy process.La présente invention concerne un système d'irradiation de rayonnement comprenant un dispositif d'irradiation de rayonnement et un lit thérapeutique (300) permettant de transporter une cible à irradier vers le dispositif d'irradiation de rayonnement pour une irradiation. Le lit thérapeutique (300) comprend un élément de positionnement (52). L'élément de positionnement (52) comprend un corps de blindage (54) et un sac d'étanchéité (53) pour recevoir le corps de blindage (54). Le corps de blindage (54) comprend du silicone et un matériau de protection contre le rayonnement qui est apte à protéger d'un rayonnement. Lorsque l'élément de positionnement (52)
