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Session: Multi-Disciplinary General ePoster Viewing [Return to Session]

SpyGRT: An Open-Source Low-Cost Surface Guidance System for Radiotherapy Research

Y Ben Bouchta*, C Sengupta, M Gardner, T Reynolds, P Keall, University of Sydney, Sydney, NSW, AU,


PO-GePV-M-218 (Sunday, 7/10/2022)   [Eastern Time (GMT-4)]

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Purpose: Surface Guided Radiation Therapy (SGRT) is a technology in which optical cameras acquire a 3D surface image of the patient. The use of SGRT in the clinic has increased dramatically in the last few years as it can reduce patient set-up time and provide real-time motion monitoring during treatment. However, research into novel application of SGRT is currently difficult as clinical systems are expensive and use proprietary algorithms. In this work, we present SpyGRT, a Python-based open-source surface-guidance code that has been especially developed for research into novel SGRT applications and which can be used to build a low cost SGRT research system.

Methods: We validated the translational accuracy of the SpyGRT code for two anatomical sites: the head, and pelvis. A robotic motion platform capable of submillimeter accuracy and a head phantom was used to measure the head motion tracking accuracy of the SpyGRT code. To validate accuracy of our code in tracking pelvic motion, we imaged a volunteer in a supine position on a moving robotic couch capable of planar motion with submillimeter accuracy. All surface images used for this this study were acquired using two Intel RealSense D415 cameras controlled by the SpyGRT code.

Results: We found that SpyGRT had a mean absolute translational error of 0.3 ± 0.2mm in the longitudinal axis, 0.4 ± 0.2mm in the transversal axis and 0.6 ± 0.1mm in the sagittal axis for head motion. For pelvic motion, the mean absolute translational error was of 1.2 ± 0.9mm in the longitudinal axis, 0.4 ± 0.3mm in the transversal axis and 0.6 ± 0.3mm in the sagittal axis.

Conclusion: SpyGRT is a new surface imaging research code that can be used as the basis of a low cost SGRT research system capable of submillimetre precision for multiple treatment site.

Funding Support, Disclosures, and Conflict of Interest: This project was funded by Cancer Australia, funded by the Australian Government


Surface Matching, Optical Imaging, Image-guided Therapy


TH- RT Interfraction Motion Management: Development (new technology and techniques)

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