An image guided small animal stereotactic radiotherapy system

Area of Science:

• Medical Physics
• Radiation Oncology
• Preclinical Research

Background:

• Small animal radiotherapy requires precise tumor targeting and healthy tissue sparing.
• Existing systems may lack the necessary image guidance and precision for advanced radiobiology studies.

Purpose of the Study:

• To develop and evaluate an image-guided small animal arc radiation treatment system (iSMAART).
• To achieve highly precise radiation targeting for focal tumor irradiation in preclinical models.

Main Methods:

• Development of the iSMAART system with upright animal positioning, stationary X-ray tube and detector, and a rotatable/translational stage.
• Utilized onboard cone-beam computed tomography (CBCT) for image guidance and targeting verification.
• System performance assessed using phantoms and tumor-bearing animals, evaluating imaging, guidance, positioning, and targeting accuracy.

Main Results:

• Onboard CBCT provided good signal, contrast, and sub-millimeter spatial resolution.
• Iodine contrast CBCT accurately delineated orthotopic prostate tumors.
• Animal positioning accuracy was ~0.3 mm, with overall targeting precision within 0.4 mm.
• Delivered stereotactic radiation beams conformal to tumor targets from multiple angles.

Conclusions:

• The iSMAART system enables image-guided, precision radiation delivery for focal tumor irradiation in small animals.
• This technology facilitates healthy tissue sparing, crucial for radiobiology research.
• The system offers an affordable solution for advanced preclinical radiotherapy.