Design, performance characteristics and application examples of a new 4D motion platform

Area of Science:

• Medical Physics
• Radiation Oncology
• Medical Imaging

Background:

• Radiation therapy (RT) requires precise tumor targeting, which is challenged by respiratory motion.
• Existing quality assurance (QA) methods for respiratory motion management devices need robust simulation tools.
• Accurate simulation of breathing patterns is crucial for training and research in 4D radiation therapy (4DRT).

Purpose of the Study:

• To introduce and evaluate a three-dimensionally movable motion phantom for RT applications.
• To assess the phantom's performance in simulating respiratory motion for QA, training, and research.
• To validate the phantom's accuracy in replicating various breathing patterns and anomalous events.

Main Methods:

• Development of a 3D motion platform driven by three computer-controlled linear motors.
• Integration of add-on components for dosimetric measurements (e.g., ArcCHECK).
• Performance evaluation using simulated normal breathing patterns (sinusoidal curves) and anomalous events (coughing, baseline drift).

Main Results:

• The motion phantom offers a motion range of 40 × 50 × 50 mm with high velocity and acceleration capabilities.
• Simulated motion path accuracy was measured within 0.521 mm, even with a 20 kg load (ArcCHECK).
• The phantom successfully simulates normal breathing and anomalous respiratory events.

Conclusions:

• The developed 3D motion phantom meets the requirements for QA of respiratory motion management devices in RT.
• The phantom is suitable for training clinical staff and advancing 4DRT research.
• Its high accuracy and versatility make it a valuable tool for radiation oncology.