What is Cyberknife cancer treatment ?
Cyberknife is a non-invasive frameless stereotactic radiosurgery system that treats tumors anywhere in the body. Cyberknife is the robotic system that utilizes the skeletal structure of the body as a reference, eliminating the need for the invasive frame for intracranial lesions. It can be applied to the whole body including the targets in medulla spinallis and spine using one or multiple fraction. For a video explaining Cyberknife as an alternative cancer treatment, please see: cyberknife cancer treatment.
General patient characteristics
Three basic characteristics are important for patient selection in Cyberknife®
similar to other radiosurgery applications. Firstly, patients should have reasonable overall survival after radiosurgery treatment. Benign lesions are in this group and are easily treated with radiosurgery. Patients who have malign tumors and expected life is more than 6 months could be treated with radiosurgery. Secondly, capacity of patient cooperation to all diagnostic and treatment stages is important. Treatment time takes longer for patients who do not have complete cooperation. At last, patients whose tumor borders are clearly verified with radiological scans are good candidates for radiosurgery treatment.
Cyberknife target field size
Target field size is one of the important parameter for Cyberknife®
as in all other radiosurgery implementations. Acceptable lesion diameter is around 3 cm for intracranial lesions. Also, some institutes expand this until 3.5 cm.
Treating larger field sizes for some lesions can be possible with some of the features of Cyberknife®. We believe that especially for irregularly-shaped lesions, a non-isocentric plan can generate greater conformality than an isocentric plan. More homogenous dose distribution can be achieved while sparing the organ at risk. However clinical judgement should be exercised with all treatment plans. In addition, Cyberknife®
eliminates the need for the frame used in traditional radiosurgery system. Because of that irregular-shaped lesions around 4.5-5 cm diameter can be treated with Cyberknife®
using one or multiple fractions.
Proximity of critical structures
Lesion proximity to the critical structures is an important criteria for radiosurgery treatments. Some of the examples for critical structures are optic/vestibular/cochlear nerves and brainstem. Adjacent critical structures to the tumor can be treated with extreme precision and accuracy in Cyberknife therapy.
system. The manipulator enables unlimited beam positions, which provides access to many tumors that are unreachable by other radiosurgery systems. System can continuously track, detect and correct tumor and patient movement throughout the treatment.
Possibility of staged radiosurgery
It is very difficult to deliver high doses at once for some cases, especially for big
tumor size (around 4-5 cm diameter) and tumors near the critical structure. Total dose can be divided into multiple fractions and complication risk can be reduced with Cyberknife®
radiosurgery system.