Development of a novel radiotherapy motion phantom using a stepper motor driver circuit and evaluation using optical...

Area of Science:

• Medical Physics
• Radiotherapy Technology

Background:

• Patient motion during radiotherapy significantly impacts treatment quality.
• Gating techniques improve target coverage and organ-at-risk sparing.
• Motion phantoms are crucial for quality control and assurance of gating systems.

Purpose of the Study:

• To design and construct a novel motion phantom for accurate simulation of patient breathing motion.
• To enable end-to-end quality control of radiotherapy gating systems.
• To facilitate patient-specific quality assurance for motion-managed treatments.

Main Methods:

• A motion phantom was designed using a stepper motor driver circuit.
• The phantom was programmed with real patient breathing data and custom signals.
• Performance was evaluated by tracking motion with a Sentinel™ system and comparing results to original data.

Main Results:

• The phantom accurately reproduced patient breathing curves with a mean error of -0.09 mm and standard deviation of 0.24 mm.
• Square wave signals were reproduced with high accuracy (mean error -0.03 mm, std dev 0.04 mm).
• The phantom demonstrated reliable performance in simulating breathing motion.

Conclusions:

• The in-house developed motion phantom accurately reproduces patient breathing data.
• It offers a versatile platform for quality control of gating systems and dosimetric assessments.
• This tool enhances the quality assurance process in motion-managed radiotherapy.