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Radiotransparent Audiovisual Systems During Treatment for Patient Relaxation, Active Feedback, and Cross-Language Communication: Current Designs, Multi-Year Clinical Experience, Future Directions

A Yu , T Juang , L Skinner , K Bush*, Stanford University, Stanford, CA


(Sunday, 7/29/2018) 5:05 PM - 6:00 PM

Room: Karl Dean Ballroom A2

Purpose: Radiotransparent audiovisual display systems, known as AVATAR (AudioVisual Assisted Therapeutic Ambience in Radiation Therapy), are used at our institution during radiotherapy to replace anesthesia in a large fraction of pediatric cases, to provide breath-hold feedback, and to assist with cross-language communication. Here we present an update on the clinical results, current technology, and future directions.

Methods: Portable projectors and thin screens provide a convenient way to display video during C-arm linac radiotherapy treatments. The challenge is to provide a useable system that is durable and minimally impacts the radiation dose. Several mounting, projector, and display systems have been investigated. This includes mirror displays, plastic, carbon fiber, foam board, and paper-based screens. Optimal design is a compromise between optical properties, dose transparency, and usability. A website, which acts as the home page for the AVATAR system containing display links, setup instructions, and construction guidelines has been made available. This includes a commercially available parts list and 3D printable design files.

Results: Since publication of our initial implementation, the dose buildup of the screens has been reduced by a factor of five such that direct 6 MV radiation beams through the screens now produce less than 2% excess surface dose. Excess attenuation from the screens at 10 cm depth for a 6 MV beam was found to be less than 0.2%. Audio has been improved to enable translation via a combination of text and audio messages. Current designs, detailed dose measurements, issues discovered, and workflow considerations will be presented.

Conclusion: Audiovisual display systems during treatment offer huge potential to improve the patient experience, cross language barriers, and improve motion control via feedback. Here the challenges and currently implemented solutions are provided.

Funding Support, Disclosures, and Conflict of Interest: Funded by an internal Stanford healthcare quality improvement grant.


Patient Movement


TH- External beam- photons: Motion management (intrafraction)

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