Murine Lung Tumor Measurement Using Respiratory-Gated Micro-Computed Tomography

Abstract

The authors explored micro-computed tomography (micro-CT) to quantify lung tumor number and volume in a specific genetic mouse model for lung cancer. The authors used K-ras mice, which develop lung adenomas and adenocarcinomas through somatic activation of the K-ras oncogene. Tumor number measured using micro-CT and were compared at necropsy (n = 38 mice). Tumor volume measurement precision (n = 39 mice) and accuracy (multiple tumors from a single mouse) were evaluated. Serial lung tumor volume was assessed in a pilot group (n = 8) of mice in vivo. Tumor number assessed at necropsy and using micro-CT were significantly correlated. Lung tumor volume measurements were both reproducible (2% operator variability) and accurate (6% average error). Strikingly, we observed both tumor growth and shrinkage within individual mice. Serial measurements provided evidence of tumor heterogeneity, an unexpected finding given the uniformity of the initiating genetic event. Micro-CT may become a powerful tool for murine lung cancer research in vivo.