Met inhibitor and/or nucleotide sequence encoding a Met inhibitor for use in the treatment of patients suffering from a cancer for reducing and/or abrogating patients resistance to radiotherapy, wherein the Met inhibitor is selected among: i) an anti-Met monoclonal antibody, ii) a genetically engineered antibody containing the complementarity determining regions (CDRs) of the anti-Met monoclonal antibody, and iii) a fragment of (i) or (ii) containing the complementarity determining regions (CDRs) of the anti-Met monoclonal antibody, or combinations thereof.