CyberKnife radiation therapy as a platform for translational mouse studies

Area of Science:

• Oncology
• Radiation Oncology
• Preclinical Cancer Research

Background:

• Radiation therapy (RT) is a cornerstone of cancer treatment.
• Genetically engineered mouse models (GEMM) are crucial for studying human diseases.
• Conventional linear accelerators are inadequate for advanced image-guided radiation therapy (IGRT) in GEMM.

Purpose of the Study:

• To evaluate the CyberKnife (CK) platform for IGRT of GEMM-derived non-small cell lung cancer (NSCLC) tumors.
• To assess the precision and feasibility of CK-based IGRT in a preclinical setting.

Main Methods:

• GEMM-derived Kras^LSL-G12D/+/Trp53^fl/fl NSCLC flank tumors were irradiated using the CK platform.
• IGRT was delivered at doses of 2, 4, 6, and 8 Gy with field sizes of 5-12.5 mm.
• Xsight Spine Tracking was utilized for precise tumor targeting.

Main Results:

• A planning target volume (PTV) margin of 0 mm was sufficient for CK-based IGRT of murine tumors.
• Higher RT doses (6-8 Gy) significantly reduced tumor-infiltrating leukocytes (TIL) within 1 hour compared to lower doses (2-4 Gy).
• Even low-dose RT (2 Gy) led to TIL reduction between 8-24 hours.

Conclusions:

• The CyberKnife RT system provides high-precision, targeted IGRT for murine tumors.
• This platform represents a promising advancement for translational radiation therapy research using mouse models.