Correlating EGFR Expression with Receptor- Binding Properties and Internalization of

The anti–epidermal growth factor receptor (anti-EGFR) antibody cetuximab is clinically approved for the treatment of EGFR-expressing metastatic colorectal cancer and advanced head and neck cancer. Overexpression of EGFR has also been found in more than 70 % of carcinomas of the cervix. The overall goal of this study was to determine whether 64Cu-1,4,7,10-tetraazacy-clododecane-N,N9,N$,N9$-tetraacetic acid (DOTA)-cetuximab has potential as an agent for measuring EGFR concentration by PET imaging in cervical cancer tumors. Methods: Cetuximab was conjugated to the bifunctional chelator DOTA and labeled with 64Cu. EGFR messenger RNA (mRNA) expression was corre-lated with EGFR densities on the cell surface of 5 different cervi-cal cancer cell lines and with receptor function, measured by internalization of 64Cu-DOTA-cetuximab. Imaging in tumor-bearing mice with small-animal PET was performed using th