Mapping lung cancer ventilation dynamics using functional imaging and lung mechanics

In vivo models that replicate and reproduce human lung cancer and its response to therapy are necessary for the development of new therapeutic strategies and understanding drug resistance. Imaging lung tumors in live animals to monitor tumor growth and response to therapy is challenging owing to the location of the lungs and their constant movement during breathing. X-ray velocimetry (XV) is a novel functional lung imaging technique that maps regional lung expansion during breathing, providing spatial information on where ventilation changes occur. The aim of this pilot study was to use XV and flexiVent lung mechanics assessments to determine the effect of tumor growth on lung function in mice at 2 or 3 weeks post tumor induction and to evaluate the efficacy of these two tools. Histological analysis showed that tumor growth was not uniform between animals. At 3 weeks post tumor induction, some XV ventilation and flexiVent lung mechanics parameters were significantly different from baseline. Both techniques gave metrics that correlated with the tumor counts from the histology. In some mice, XV revealed localized regions with altered expansion rates.