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A Novel Six-Degrees-Of-Freedom (6DoF) Robotic Motion Phantom for Quality-Assurance (QA) to Test Advanced Radiotherapy Delivery Approaches

V Caillet1*, S Alnaghy2 , A Kyme3 , D Nguyen4 , R O'Brien5 , J Booth6 , P Keall7 , (1) ACRF Institute X, University Of Sydney, NSW, (2) ,,,(3) The Univeristy of Sydney, Sydney, NSW, (4) The University of Sydney, Eveleigh, NSW, (5) University of Sydney, Camperdown, NSW, (6) Royal North Shore Hospital, St Leonards, ,(7) University of Sydney, Camperdown, NSW


(Thursday, 8/2/2018) 10:00 AM - 12:00 PM

Room: Davidson Ballroom A

Purpose: To develop and clinically validate a prototype fully flexible robotic motion phantom that mimics patient motion for motion adaptive radiotherapy quality assurance (QA).

Methods: A novel robotic motion phantom was built using a UR3 robotic arm holding a custom-made phantom with embedded Calypso transponder beacons. An in-house software application was developed to transform real patient target motion data into the robots coordinate system to mimic tumour motion. A variety of prostate, liver, and lung motion traces were selected representing a spectrum of motion undergone by tumours during treatment. The selected traces were executed on the robotic motion phantom with the motion externally recorded using the Calypso tracking system. The Calypso recorded motion was used as the ground truth and compared with the robotic motion phantoms output data. Several geometric QA tests were used based on previously published testing procedures from a commercial motion phantom (Hexamotion).

Results: The static localization accuracy for translation and rotation was found to be 0.37 mm and 0.36° respectively, within the uncertainty of the Calypso recorded positions of 0.5 mm for each direction of motion. Preliminary results of the robotic motion phantom prototype have shown a geometric accuracy within 0.5 mm and 1° for translation and rotation respectively.

Conclusion: A novel 6DoF robotic motion phantom was developed to mimic real physiological patient tumour motion. The geometric accuracy was characterized using a commercially available motion adaptive radiotherapy system (Calypso). For the first time, accurately mimicking patient tumour motion and measuring the radiation dose in dynamic environments such as those existing in the human body can be achieved with this device.

Funding Support, Disclosures, and Conflict of Interest: This work receives funding from Cancer Australia. S Alnaghy is funded by Cancer Australia, D T Nguyen is funded by an NHMRC and a Cancer Institute NSW Early Career Fellowship. P Keall is funded by an NHMRC Senior Principal Research Fellowship.


Quality Assurance, Target Localization, Radiation Therapy


Not Applicable / None Entered.

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