There are several devices, modifed linear accelerators (linac) systems, in our area that are capable of delivering radiation, but that do not automatically and continously adapt to tumor motion caused by organ movement or breathing and require more multiweek treatment sessions vs. 1-5 sessions or "fractions" with CyberKnife. The number of fractions depends on several factors, including the size of the lesion, location in the body, and your unique treatment plan developed by the multidisciplinary practitioners.

 

	CyberKnife®	Gamma Knife®	Other Linac Systems (ie., Novalis®, Varian Trilogy®, TomoTherapy®)
Continuously adapts to lesion motion caused by organ movement	Yes	N/A	No
Continuously adapts to lesion motion caused by breathing (respiratory tracking)	Yes	N/A	Varian Trilogy uses respiratory gating but does not track with radiosurgical precision; other systems do not adapt to breathing
Radiosurgery dedicated	Yes	Yes	No
Also does “conventional” radiotherapy	No	No	Yes
Anatomic area treatable with radiosurgical precision	Brain, spine, entire body	Brain	Brain, possibly other areas, depending upon system
Rigid brain or body frame required for accuracy	No	Yes	Yes
Lesion size limitation	No	Yes	No
Capable of divided treatments to better preserve adjacent tissues	Yes	No	Yes