Positron emission tomography imaging of DMBA/TPA mouse skin multi-step tumorigenesis

Many tumor cells have elevated rates of glucose uptake that can be measured quantitatively, noninvasively and repeatedly by positron emission tomography (PET) with 2-deoxy-2-[18F]-fluoro-D-glucose (18F-FDG). Clinical imaging with 18F-FDG PET has been used for detection and staging of primary and metastatic tumors. High-resolution microPET scanning and murine cancer models make it possible to analyze longitudinally glucose metabolism during the appearance, development and progression of individual experimental tumors. In this study, we used 18F-FDG microPET and micro computerized tomography (microCT) to investigate glucose uptake in the DMBA/TPA chemically-induced multistage mouse skin carcinogenesis model. 18F-FDG uptake is significantly higher in all papillomas than in surrounding skin. Elevated 18F-FDG uptake is observed when tumors can be identified morphologically, but not before. Although 18F-FDG uptake is high in all fully invasive, malignant skin squamous cell carcinomas, uptake in papillomas and microinvasive malignant squamous cell carcinomas is variable and does not exhibit any correlation with tumor stage.