3D printer generated thorax phantom with mobile tumor for radiation dosimetry

Area of Science:

• Medical Physics
• Radiotherapy
• Medical Imaging

Background:

• Accurate radiation dose measurement is critical for effective cancer treatment.
• Simulating tumor motion during radiotherapy is essential for precise dose delivery.
• Existing phantoms often lack the ability to accurately represent moving tumors and surrounding tissues.

Purpose of the Study:

• To design, construct, and evaluate an anthropomorphic thorax phantom with a moving surrogate tumor.
• To enable accurate dose detection inside and outside the moving tumor and within surrogate lung tissue.
• To compare measured radiation doses with planned doses for a simulated radiotherapy treatment.

Main Methods:

• A 3D-printed anthropomorphic thorax phantom was created using patient CT scan data.
• A surrogate spherical tumor, controlled by a 3D linear stage, simulated breathing motion.
• Sawdust was used to emulate lung tissue, and radiochromic film was used for dosimetry.

Main Results:

• The phantom accurately simulated patient anatomy and allowed for dose detection in moving and static conditions.
• Gamma analysis showed 8.8% and 5.5% failure rates for moving and static measurements, respectively.
• Calculated dose distributions incorporating tumor motion phase improved agreement between measured and intended doses.

Conclusions:

• The developed anthropomorphic phantom with a moving surrogate tumor is a valuable tool for radiotherapy research.
• It facilitates accurate dose assessment in dynamic treatment scenarios.
• Incorporating tumor motion into dose calculations enhances the accuracy of radiotherapy planning and delivery.