CEACAM5 and neoplasm: The application of 99mTc-labeled monoclonal antibody fragments, such as99mTc-labeled arcitumomab (IMMU-4 murine monoclonal antibody fragments against CEA) and 99mTc-nofetumomab merpentan (monoclonal antibody fragment of the pancarcinoma murine antibody NR-LU-10) have been used in nuclear medicine imaging but have only been very limitedly investigated for tumor detection during radioguided surgery [105-107].