Comparison of (18)F-labeled CXCR4 antagonist peptides for PET imaging of CXCR4 expression.

Purpose CXCR4 is overexpressed on tumor cells from many types of human cancers. A high level of CXCR4 expression often correlates with poor prognosis, chemotherapy resistance, and metastasis. The development of CXCR4-specific radiotracers for positron emission tomography (PET) imaging will allow in vivo evaluation of receptor expression level for diagnosis or therapeutic evaluation.