Purpose: The geometric and dosimetric impact of tumor translation and rotation, or 6-degree-of-freedom (6-DoF) motion, in radiation therapy is becoming increasingly important. Since there is currently no commercial 6-DoF solution that could reproduce patient-measured motion, we designed, built and programmed a robot-based system for 6-DoF Image-guided Radiation Therapy (IGRT) research and Quality Assurance (QA). To enable advancement of intrafraction motion management in our community, we have made the complete package open-source. The purpose of this work is to describe the applications of the 6-DoF system, the research results and the open-source repository.
Methods: The 6-DoF system consists of a six-axis robotic arm (Universal Robot, UR3), an acrylic phantom, a custom-base plate to mount the robotic phantom onto the treatment couch and a software application which controls the robotic phantom to reproduce the patient-measured tumor motion. The integrated system is capable of accurately mimicking patient-measured tumor traces to provide precise 6-DoF QA for real-time IGRT approaches. The repository contains everything required to assemble a similar 6-DoF system: source code, CAD files for the phantom and hardware tools, robot specifications, bill of materials, documentation, and user-guide to operate the system, and, step-by-step QA procedure.
Results: The 6-DoF system has been used successfully for several applications including geometric QA tests for the real-time tumor tracking technology, Kilovoltage Intrafraction Monitoring (KIM) in two multi-center clinical trials, for prostate and liver cancer patients and evaluation of the dosimetric impact of prostate rotational motion using films.
Conclusion: The development of this system has enabled us to perform 6-DoF QA processes for KIM and it has great potential to perform QA for other real-time radiotherapy systems. Full details of the system and its application have been shared on GitHub for the benefit of the medical physics community: https://github.com/ACRF-Image-X-Institute/6-DoF-Robotic-Motion-Phantom.
Funding Support, Disclosures, and Conflict of Interest: P Keall is supported by an NHMRC Investigator (L3) grant. D T Nguyen is supported by NHMRC and Cancer Institute NSW Early Career Fellowships. Nguyen, O'Brien and Keall are listed inventors on KIM-related patents. Nguyen and Keall are stock-holders of SeeTreat Pty.
Not Applicable / None Entered.