Comparison of PET Imaging with 64Cu-Liposomes and 18F-FDG in the 7,12-Dimethylbenz[a]anthracene (DMBA)-Induced Hamster Buccal Pouch Model of Oral Dysplasia and Squamous Cell Carcinoma

Currently, 2-deoxy-2-[F-18]fluoro-d-glucose (F-18-FDG) is the gold standard radiotracer for staging of head and neck cancer; however, the low sensitivity of this tracer can impede detection of early lesions. Cu-64-liposomes accumulate in various cancers and provide both a sensitive tracer and an indication of the biodistribution of nanotherapeutics. Here, the accumulation of Cu-64-liposomes in early and established cancers is assessed and compared with F-18-FDG in a head and neck cancer model. Lesions ranging from mild dysplasia to squamous cell carcinoma were induced in a hamster model of head and neck cancer by topical application of 7,12-dimethylbenz[a]anthracene to the buccal pouch. The hamsters were imaged with micro-positron emission tomography using F-18-FDG and Cu-64-liposomes. At 24 h postinjection, Cu-64-liposome accumulation exceeded the accumulation of F-18-FDG in every pathologic grade. The lesion-to-cheek pouch (background) ratio and lesion-to-brain ratio were also higher for Cu-64-liposomes than for F-18-FDG. Imaging of a nanotracer such as Cu-64-liposomes can improve the visualization of head and neck tumors. Accumulation of liposomal particles in head and neck tumors over various pathologic grades averaged 3.5 %ID/cc demonstrating the potential for liposomal therapy with targeted chemotherapeutic agents.