Radioactive EGFR Antibody Cetuximab in Multimodal Cancer Treatment: Stability and Synergistic Effects With Radiotherapy

131I-Erbi was stable for ≤72 h. Radiotherapy led to increased tumor cell uptake of 131I-Erbi. Radiotherapy and 131I-Erbi synergistically inhibited tumor cell proliferation. These results provide the prerequisite data for a planned in vivo study of whole brain radiotherapy plus cetuximab for brain metastases.