Metabolic evaluation of non-small cell lung cancer patient-derived xenografts models using [18F]FDG PET: potential tools for early therapy response

PURPOSE: Lung cancer heterogeneity makes response to therapy extremely hard to predict. Patient-derived xenografts (PDXs) represent a reliable preclinical model that closely recapitulates the main characteristics of the primary tumor and could represent a useful asset to test new therapies. Here, using PET imaging, we verify how lung cancer PDXs reproduce the metabolic features of the corresponding primary tumors. METHODS: We performed longitudinal [18F]FDG-PET studies on nine different PDXs, obtained by implants of primary cancer fragments harvested from patients. Max [18F]FDG uptake values of the lesion for each group were calculated and compared to corresponding patient's uptake. RESULTS: Different PDXs showed variable tumor growth rate and [18F]FDG uptake confirming the preservation of individual characteristics. A good intra-group reproducibility of PET measurements was observed. Furthermore, the subgroup of PDXs originating from primary tumors with higher metabolic rate displayed a rank order of [18F]FDG uptake similar to that of patients' original SUV. CONCLUSION: PDXs reproduced the original glucose metabolism of primary lesions and represent therefore a promising preclinical model also for the early assessment of therapy efficacy.