CyberKnife® Radiosurgery: A Higher Order of Precision The CyberKnife® Synchrony®respiratory tracking system locks onto implanted gold fiducial markers and correlates their position with the respiratory cycle as determined by optical tracking, to track the targeted lesion with 1.5 mm accuracy throughout the entire breathing cycle, allowing a much smaller applied margin compared with other radiation delivery systems. This gives CyberKnife® the distinction of being the only device that currently brings radiosurgical precision to a respiration-induced moving target such as the pancreas.