Cyberknife: Robotic Radiosurgery Shows Promise for Accurately Targeting and Treating Cancerous Lesions

Ariana Gopal

Cyberknife: Robotic Radiosurgery Shows Promise for Accurately Targeting and Treating Cancerous Lesions

              Cyberknife is a form of robotic radiosurgery that is geared toward precisely targeting cancerous masses in the body.  Paired with real-time imaging, the radiosurgery is delivered from an adjustable robotic arm that points a high dose linear beam of radiation to a target site (Shinohara, 2016).  Before the radiation therapy is applied to the target site, an individualized treatment plan must be created.  First, an imagining technique such as an MRI is evaluated to determine how much radiation therapy can be handled by the specific cancer site (Chang et al., 1998). After this is established, the three dimensional geometry of the cancer lesion can be devised and used by the Cyberknife system to determine the optimum beam dosage for the cancer site, and ultimately provide the safest and most efficient treatment for the patient (Chang et al., 1998).

Past research on the Cyberknife has shown promise in its ability to successfully target cancerous lesions.  For example, a research study conducted in 2004 indicated that the Cyberknife was capable of delivering treatment at an average positional error of 0.2-0.4 mm to spinal cancer sites, indicative of how precise this radiosurgery system can be (Yu et al., 2004).  A 1998 study evaluated the efficiency of Cyberknife radiosurgery for 72 patients with cancerous tumors in the intracranial region (Yu et al., 1998).  After 9 months post-treatment, 32% of patients reported no visible tumors, 63% tumor shrinkage, and 5% tumor enlargement (Chang et al., 1998).   Additionally, research using the Cyberknife system on spinal lesions showed spinal pain improvement in over 90% of patients with no reported neurological deficits or radiation toxicity post treatment (Gerszten et al., 2004).  This study also shed light on the outpatient nature and speedy recovery time associated with Cyberknife surgery.

Since these studies were conducted, the Cyberknife has been modified to reduce treatment duration and new algorithms have been programmed to improve the system’s calculation of radiation dosage (Dieterich & Gibbs, 2011).  However, as clearly exemplified in the research above, Cyberknife procedures have predominantly been conducted on patients with cancerous lesions directly effecting aspects of their nervous system.  Additional literature can be reviewed to determine what other types of cancerous tissues have been targeted using the Cyberknife system, such as the lung and the prostate.  It would also be helpful to compare the impact of Cyberknife to other cancer treatment methods, such as traditional radiation therapy and surgery.  Nevertheless, as deduced from this current review, the Cyberknife does show promise in terms of safety, accuracy, and effectively treating cancerous lesions of the brain and spine.

Figure 1: The Preliminary Design of the Cyberknife System (Chang et al., 1998)

References

Chang, S. D., Murphy, M., Geis, P., Martin, D. P., Hancock, S. L., Doty, J. R., & Adler, J. J.  (1998). Clinical Experience with Image-guided Robotic Radiosurgery (the Cyberknife) in the Treatment of Brain and Spinal Cord Tumors. Neurologia Medico-chirurgica Neurol. Med. Chir.(Tokyo), 38(11), 780-783.

Dieterich, S., & Gibbs, I. C. (2011). The CyberKnife in Clinical Use: Current Roles, Future Expectations [Abstract]. IMRT, IGRT, SBRT Frontiers of Radiation Therapy and Oncology, 181 -194.

Gerszten, P., Ozhasoglu, C., Burton, S., Vogel, W., Atkins, B., Kalnicki, S., & Welch, W. (2004). Cyberknife Frameless Stereotactic Radiosurgery for the Treatment of Spinal Lesions: Clinical Experience in 125 Cases [Abstract]. Neurosurgery, 55(1).

Shinohara, E. (2016). Radiation Therapy: Which Type is Right for Me?

Yu, C., Main, W., Taylor, D., Kuduvalli, G., Apuzzo, M. L., Adler, J. R., & Wang, M. Y. (2004).  An Anthropomorphic Phantom Study of the Accuracy of CyberKnife Spinal Radiosurgery [Abstract]. Neurosurgery, 55(5), 1138-1149.