Quantification of Tumor Burden in a Genetically Engineered Mouse Model of Lung Cancer by Micro-CT and Automated Analysis.
Genetically engineered mouse models (GEMMs) of lung cancer closely recapitulate the human disease but suffer from the difficulty of evaluating tumor growth by conventional methods. Herein, a novel automated image analysis method for estimating the lung tumor burden from in vivo micro-computed tomography (micro-CT) data is described. The proposed tumor burden metric is the segmented soft tissue volume contained within a chest space region of interest, excluding an estimate of the heart volume. The method was validated by comparison with previously published manual analysis methods and applied in two therapeutic studies in a mutant K-ras GEMM of non-small cell lung carcinoma. Mice were imaged by micro-CT pre-treatment and stratified into four treatment groups: an antibody inhibiting vascular endothelial growth factor (anti-VEGF), chemotherapy, combination of anti-VEGF and chemotherapy, or control antibody. In the first study, post-treatment imaging was performed 4 weeks later. In the second study, mice were scanned serially on a high-throughput scanner every 2 weeks for 8 weeks during treatment. In both studies, the automated tumor burden estimates were well correlated with manual metrics (r value range: 0.83-0.93, P < .0001) and showed a similar, significant reduction in tumor growth in mice treated with anti-VEGF alone or in combination with chemotherapy. Given the fully automated nature of this technique, the proposed analysis method can provide a valuable tool in preclinical drug research for screening and randomizing animals into treatment groups and evaluating treatment efficacy in mouse models of lung cancer in a highly robust and efficient manner.
Department of Biomedical Imaging, Genentech, Inc, South San Francisco, CA, USA.
Kai H
KH
Barck
Department of Biomedical Imaging, Genentech, Inc, South San Francisco, CA, USA.
Hani
H
Bou-Reslan
Department of Biomedical Imaging, Genentech, Inc, South San Francisco, CA, USA.
Ujjawal
U
Rastogi
Department of Biomedical Imaging, Genentech, Inc, South San Francisco, CA, USA.
Timothy
T
Sakhuja
Department of Translational Oncology, Genentech, Inc, South San Francisco, CA, USA.
Jason E
JE
Long
Department of Translational Oncology, Genentech, Inc, South San Francisco, CA, USA.
Rafael
R
Molina
Department of Discovery Oncology, Genentech, Inc, South San Francisco, CA, USA.
Anthony
A
Lima
Department of Discovery Oncology, Genentech, Inc, South San Francisco, CA, USA.
Patricia
P
Hamilton
Department of Translational Oncology, Genentech, Inc, South San Francisco, CA, USA.
Melissa R
MR
Junttila
Department of Discovery Oncology, Genentech, Inc, South San Francisco, CA, USA.
Leisa
L
Johnson
Department of Biomedical Imaging, Genentech, Inc, South San Francisco, CA, USA. Electronic address: carano.richard@gene.com.
Richard A D
RA
Carano