Program Information
A Novel Quality Assurance Method to Find and Verify the Linear and Rotational Limits of the Cyberknife M6 Fiducial Based 6D Synchrony Respiratory Tracking
G Gibbard1*, C Shang2 , (1) Florida Alantic University (2) Boca Raton Regional Hospital, Boca Raton, FL
Presentations
SU-I-GPD-J-1 (Sunday, July 30, 2017) 3:00 PM - 6:00 PM Room: Exhibit Hall
Purpose: A novel test to find and verify the linear and rotational limits of the Cyberknife M6 fiducial based 6D Synchrony® Respiratory Tracking
Methods: The maximal synchronized linear and rotational tumor displacements for respiratory motion were simulated using a modified QUASAR™ Respiratory Motion Phantom with six 1x5mm gold fiducials embedded around the target. The tracking model used the four best visualized fiducials. The maximal motion tracking ranges tested were measured at different breathing speeds (10/ 20/28 cycles/minute) for the Y, X, roll, pitch, a combined Z/Y and yaw/roll motions. The default maximum values the tracking system can handle are 50mm in the X, Y and Z and 1.5o, 1.5o and 3.0o in the Pitch, Roll, and Yaw rotations. An End to End test was performed with roll orientation and then analyzed.
Results: The successfully trackable motion ranges were found to be 41.7mm, 41.5mm & 30.2mm and be 1.5o, 1.5o, and 3.0o respectively for the X, Y, and Z directions and the for Roll, Pitch & Yaw rotations at three different respirational speeds (P-value > 0.05) and (P-value > 0.05). For 28 cycles per minute motion, exposure time for the image acquisition was reduced to 50 msec from the default 100 msec to detect all tracking fiducials. The analyzed E2E test with a roll motion had a total targeting error of 0.59mm.
Conclusion: The limitations and accuracy of 6D fiducial based Synchrony® Respiratory Tracking on the Cyberknife M6 with default certainties have been successfully tested at three different cycles/min and verified by an End to End test on a modified QUASAR™ Respiratory Motion Phantom. For the high-speed motion, short imaging exposure time is suggested by this investigation. This work provides an independent quality assurance to verify the Synchrony® Respiratory Tracking, were faster image acquisition is suggested for tracking a fast-moving target.
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