Metabolic Evaluation of Non-Small Cell Lung Cancer Patient-Derived Xenograft Models Using 18F-FDG PET: A Potential Tool for Early Therapy Response.

Abstract

Lung cancer heterogeneity makes response to therapy extremely hard to predict. Patient-derived xenografts (PDXs) are a reliable preclinical model that closely recapitulates the main characteristics of the parental tumors and may represent a useful asset for testing new therapies. Here, using PET imaging, we investigated whether lung cancer PDXs reproduce the metabolic characteristics of the corresponding parental tumors. We performed longitudinal ¹⁸F-FDG PET studies on 9 different PDX groups obtained by implanting primary-cancer fragments harvested from patients into mice. The SUV_max of each PDX was calculated and compared with the SUV_max of the corresponding parental tumor. Tumor growth rate and uptake varied among the different PDXs and confirmed the preservation of individual characteristics. The intragroup reproducibility of PET measurements was good. Furthermore, PDXs from tumors with a higher metabolic rate displayed a rank order of uptake similar to that of the parental tumors. PDXs reproduced the glucose metabolism of the parental tumors and therefore represent a promising preclinical model for the early assessment of therapy efficacy.