Visually guided respiratory motion management for Ethos adaptive radiotherapy.

Area of Science:

• Medical Physics
• Radiation Oncology
• Image-Guided Therapy

Background:

• Ethos adaptive radiotherapy (ART) utilizes AI for planning and high-quality cone-beam computed tomography (CBCT).
• Effective respiratory motion management is crucial for abdominothoracic CBCT quality and tumor control during Ethos ART.
• A commercial respiratory motion management solution was not integrated into the institutional Ethos system.

Purpose of the Study:

• To develop and implement an institutional visually guided respiratory motion management system for Ethos ART.
• To coach patients in regular breathing or breath-hold during intrafractional CBCT and beam delivery.
• To mitigate motion artifacts and enhance tumor motion control in Ethos ART.

Main Methods:

• Developed a three-component system: respiratory motion detection, in-room display, and motion trace management software.
• Utilized an air pressure sensor for real-time respiratory motion detection.
• Implemented an extended screen and projector for visual patient guidance within the Ethos ART workflow.

Main Results:

• The system successfully detected patient respiratory motion in real time.
• Commercial or in-house software managed motion trace display, visualization, and patient guidance.
• Consistent respiratory motion traces and organ positions on intrafractional CBCTs confirmed clinical suitability.

Conclusions:

• An institutional visually guided respiratory motion management system was successfully implemented for Ethos ART.
• The developed system is easily applicable to Ethos ART.
• The solution can be adapted for other closed-bore systems like CT and MRI with appropriate sensors.