[en] The principle of radioimmunotherapy is to vectorize radioisotopes to the vicinity of tumor cells where radiation can destroy these targets. The most currently established protocols use beta-emitters. Recently, new RIT approaches using alpha radiation have been developed. These types of radiation, unlike beta emissions, have a high LET, i.e. the energy deposit related to the emission of an alpha particle is high and is performed over a short pathway of several tens of lm. Thus, this type of emission allows very localized irradiation to be performed, while preserving surrounding tissues, and cellular toxicity is achieved with only a few disintegrations at the cell surface. Unlike beta-emitters, alpha-emitters, because of their short range of action, seem more suitable for the treatment of diffuse cancers or micro metastasis subsequent to ablation of a primary tumour. However, the few radionuclides required for cell destruction in this case require very specific targeting of tumor cells. To date, alpha RIT is still at a pre-clinical stage of development: the radiolabeling methods need to be optimized to ensure in vivo stability of the radio-pharmaceuticals. The modalities of administration of radiolabeled antibodies in animal models require also to be improved for delivering higher doses to tumor targets. A comprehensive analysis of the specific events occurring at cell or tissue level in response to alpha irradiation would be of great interest in order to define the best therapeutic association, chemotherapy or the possibilities of initiating immune response to tumors in patients treated by alpha-RIT. (authors)