Radioconjugacion internalizing antibody.

Composition for internal labeling a cell, comprising a ligand which specifically binds to EGFRvIII and is internalized by the cell, wherein the ligand is selected from the group consisting of an antibody, a fragment of an antibody, and a synthetic polypeptide ; an oligopeptide comprising at least one amino acid residue positively charged and at least a residue D-amino acid, so that the oligopeptide does not comprise two or more L-amino acids contiguous, wherein said oligopeptide is covalently bound to the ligand ; and a marker that is covalently attached to the oligopeptide.