Murine lung tumor measurement using respiratory-gated micro-computed tomography

Area of Science:

• Oncology
• Medical Imaging
• Genetics

Background:

• K-ras genetically engineered mouse models are crucial for studying lung adenocarcinoma.
• Accurate quantification of tumor burden is essential for evaluating therapeutic efficacy.

Purpose of the Study:

• To evaluate micro-computed tomography (micro-CT) for quantifying lung tumor number and volume in K-ras mice.
• To assess the precision and accuracy of micro-CT for tumor volume measurements.
• To investigate serial changes in lung tumor volume in vivo.

Main Methods:

• K-ras mice were utilized, developing spontaneous lung adenomas and adenocarcinomas.
• Tumor number was quantified using micro-CT and compared with necropsy findings.
• Tumor volume measurement precision and accuracy were assessed.
• Serial in vivo tumor volume was monitored in a pilot cohort.

Main Results:

• Micro-CT demonstrated a significant correlation with necropsy for tumor number quantification.
• Lung tumor volume measurements exhibited high reproducibility (2% operator variability) and accuracy (6% average error).
• Serial imaging revealed dynamic tumor behavior, including both growth and shrinkage within individual mice.

Conclusions:

• Micro-CT is a powerful and accurate tool for quantifying lung tumors in K-ras mouse models.
• The study revealed unexpected tumor heterogeneity, challenging assumptions based on uniform genetic initiation.
• Micro-CT facilitates in vivo longitudinal studies of lung cancer, offering insights into tumor dynamics.