by Jay Lieberman, DPM
PRESENT Editor

One of our goals in Residency Insight is to expose the residency community to new and innovative technologies.  Cyberknife is one of the newest forms of stereotactic radiosurgery available today. 

Stereotactic radiosurgery (SRS) has been used for more than 30 years for the non-invasive treatment of benign and malignant tumors, vascular malformations and other disorders of the brain.  It concentrates radiation on the tumor being treated but limits exposure to the normal surrounding tissue. 

S.R.S allows treatment close to critical structures because the targeting is precise.  In some instances, only one treatment is required.  Patients occasionally need a small number of fractionated treatments.

Cyberknife represents an advanced approach to radiosurgery.  It uses a lightweight linear accelerator mounted on a robotic arm.  The advanced image guidance technology tracts patient and target position during the treatment, ensuring accuracy without the use of an invasive head frame.  The robotic arm provides multiple targeting zones and will adjust to compensate for patient movement.  Conventional S.R.S systems confirm the correlation of the target within the reference system only once.

The system is based on CT Scanning.  MR images can be fused with the CT to provide optimal information on soft tissue as well as skeletal anatomy.  The image guidance system compares the live images (radiographs) with the CT information to determine the location of the tumor.  This information is transmitted to the robot to initialize the pointing of the linac beam.  This approach offers some maneuverability in targeting.

The accuracy and precision of the Cyberknife can help target areas that may not be suitable for treatments with traditional surgery, radiation therapy, or older radiosurgery systems like the Gamma Knife.

Cyberknife with Dynamic Tracking Software (DTS) is cleared to provide radiosurgery for lesions anywhere in the body when radiation treatment is indicated.  The procedure is commonly done as an outpatient.  The treatment usually lasts 1 or 2 hours and is virtually painless.

I'm curious to see what the future will hold for this procedure in foot and ankle surgery.

For additional information, refer to:

Accuray - CyberKnife® Stereotactic Radiosurgery System using image-guided robotics.