CyberKnife is a radiation therapy delivery system which utilizes the principles of Stereotactic Image Guided Radiosurgery. It is a highly precise, image guided radiation therapy delivery system capable of taking care of the motion during treatment (‘Intra-fraction’). CyberKnife can treat tumours in almost any part of the body, deliver high dose of radiation precisely to the target and deliver minimal dose to the adjacent normal tissue, hence have minimal toxicity. Total treatment duration is only few days (usually 5 days), whereas it is usually 6 to 7 weeks in conventional radiation therapy treatment. Other instruments that fall under the category of Stereotactic Radiosurgery Systems include Axesse, Gamma Knife, Novalis, Primatom, Synergy, X -Knife, TomoTherapy and Trilogy.

The major speciality of CyberKnife treatment is the high precision of treatment, real time image guided therapy, minimal acute toxicity, non invasive(frameless) and CyberKnife can deliver high dose of radiation in short time (Hypofractionated radiation therapy).The accuracy profile of cyberknife is well ahead of the other technologies in its category, the doses can be delivered by cyberknife at sub-millimetre accuracy for static lesions and better than 2 mm accuracy to targets that move with respiration.

CyberKnife is not yet an accepted treatment for all major cancers and tumors. Though it is growing in popularity and its effectiveness is becoming more widely accepted, it is still primarily an option for patients who cannot be treated any other way. There is some evidence that over the next several years, CyberKnife will become the gold standard for the way cancer patients are treated.

If considered based upon cancer site, the neoplastic lesions of CNS, head and neck, lung, liver, pancreas and prostate form strong contenders to be evaluated for treatments under cyberknife. Based upon projected incidence, 8,60,782 new cancer patients in India form potential contenders and atleast 1-2% of these can be benefitted by cyberknife technology each year.

The following graph shows the increasing trend of cyberknife installations across the globe from year 2006 through 2011. A linear trend of growth has been observed which shows increasing popularity of the technology among the patients and doctors.

With increasing acceptance, there has been steady rise in the prospective studies and academic publications showing the effectiveness of cyberknife.on various types of lesions requiring radiosurgery. Based on this research, the use of radiosurgery is expanding and becoming standard of care treatment for many conditions.

Currently there are around 225 cyberknife installation around the globe with United States(138 CK installations) having the highest number of cyberknife installations followed by Japan(22 CK installations). As more and more conclusive data will be available demonstrating the effectiveness of this modality, we will see more installations and more cases being treated by cyberknife.

The average worldwide growth rate over the past five years for CyberKnife lung treatments was 80 percent and prostate treatments was 113 percent. This strong and sustained growth demonstrates clinicians’ increasing recognition of the System’s unique benefits in treating tumors which lie in difficult areas of body or that move throughout treatment with respiration or other bodily functions.

Current clinical trials are exploring the use of CyberKnife for the treatment of breast and other cancers. The technology is ever advancing; fields beyond cancer treatment are being explored including treatment of Parkinson’s, essential tremors and cardiac applications such as rhythm aberrancies.

The number of cyberknife installations per million population is highest for USA with 0.44 CK installations while Taiwan has around 0.21 installations per million population followed by Japan which has around 0.17 installations. More than One lakh patients have been treated by cyberknife worldwide. Around 50% of the total radio surgeries by cyberknife have been done in US alone. Even countries like UK and Canada which have highly controlled publically funded health systems have invested in cyberknife after rising demands from public and the doctors. One of the major clinics called The Harvey Clinic in UK has completed around 300 procedures since the inception.

Some of the best centres in US do around 400 to 450 patients per year, ie, around 1500 sittings per year. European Cyberknife Center in Munich, Germany has treated more than 2500 patients since CK was installed in July 2005 (i.e. 500/year).

Cyberknife is a marvelous technology that offers non-invasive treatment instead of surgery and actual pain relief instead of morphine to suppress it. This has given new hope to the patients in palliative stages of cancer and the patients where surgery is not an option. The indications for treatment are evolving with some trials going on for non neoplastic ailments. In the future, Stereotactic Radio Surgery (SRS) has all the potential to develop into one of the mainstream modality for cancer therapy.