ABSTRACT
Immunoscintigraphic studies for breast cancer localization have been performed in several centers worldwide but clinical studies of radioimmunotherapy (RAIT) for metastatic breast cancer have been rare and usually unrewarding. Oncofetal antigens such as carcinoembryonic antigen represent a major group of possible RAIT targets for breast cancer. Tumor imaging requires a high target to nontarget ratio, but tumor therapy with radiolabeled antibodies is related to the cumulative radiation energy deposited per volume of cancer tissue. The development of systemic tumor-targeted radiotherapy as part of the multimodality approach to metastatic breast cancer requires a focused multidisciplinary team. Metastatic breast cancer poses a unique challenge by its variation in cell biology which is most easily summarized by the descriptor "heterogeneous". Theoretically this ideal target for tumor therapy would be tumor specific and generously expressed on all the breast cancer cells from all breast cancer patients.
