Accuray is releasing a new software package for its CyberKnife radiation system to continuously track and adjust for the natural motion of the prostate during treatment.
By intelligently increasing imaging frequency during periods of rapid and erratic prostate movement, the CyberKnife System tailors treatment delivery uniquely to the movements of the prostate throughout the treatment session. This continual assessment of prostate motion combined, with the CyberKnife System’s automatic correction for movement in real time, not only helps to ensure prescribed doses are delivered to the prostate; it also helps to ensure surrounding sensitive structures are maximally spared.
With conventional radiation delivery techniques, such as 3D conformal and arcing IMRT, large treatment margins are commonly used to ensure adequate dose coverage in the event a potential prostate shift occurs. This additional dose coverage often encompasses regions of the rectum, bladder, and urethra, increasing the risks of related toxicities and complications.
With advanced robotic technology, the CyberKnife System utilizes continual image guidance to automatically track, detect, and correct for intra-fraction motion throughout the treatment. In contrast, conventional imaging technologies, such as IGRT and cone-beam CT, can provide a high degree of precision for pre-treatment patient alignment, but the image age — or time between when the set-up image was captured and beam delivery is completed — can be 5 minutes or more. Using such imaging technologies, conventional radiation delivery systems often fail to recognize prostate movements that occur during treatment delivery, potentially resulting in considerable degradation of overall targeting accuracy.