system-familyAccurayCyberknife

Accuray CyberKnife (family)

Robot-mounted 6 MV compact linear accelerator on a KUKA industrial robotic arm — delivers non-isocentric beams to a moving target using real-time image-guided tracking. Synchrony for respiratory motion, Xsight Spine / Xsight Lung for bony anatomy, and fiducial-based tracking for soft-tissue targets. Architecturally distinct from C-arm linacs and from cobalt-source Gamma Knife. Primary clinical niches: cranial SRS frameless, spine / lung / prostate / pancreas SBRT.

History

  • 1990 — Accuray founded by John Adler at Stanford; initial concept of robotic SRS.
  • 1999 — first FDA clearance for CyberKnife.
  • 2000s — G3 / G4 generations establish the clinical platform.
  • 2012+ — CyberKnife M6 adds InCise MLC for shorter-duration treatments.
  • Late 2010s — CyberKnife S7 current generation.

Variants

  • CyberKnife G3 / G4 / VSI — earlier generations; largely displaced but still in clinical use.
  • CyberKnife M6 — InCise MLC-equipped, prior current-generation.
  • CyberKnife S7 — current generation, fastest treatment-time tier.

Shared platform characteristics

  • 6 MV X-band linac on a 6-DoF KUKA industrial robotic arm — beams from hundreds of non-coplanar directions per fraction.
  • Orthogonal kV X-ray imaging for target tracking, real-time during delivery.
  • Synchrony respiratory motion tracking — fiducial-based or fiducial-free, with the robot adjusting beam position in response to target motion.
  • Xsight Spine / Xsight Lung — bony anatomy and lung-tumor tracking without fiducials.
  • Iris variable aperture + InCise MLC (M6 / S7) — circular and conformal beam shaping.
  • Accuray Precision treatment-planning system (unified with TomoTherapy / Radixact).

Distinctive technology

  • 6-DoF robotic delivery — non-coplanar beam geometry no C-arm linac matches at this density of beam directions per fraction.
  • Real-time tracking with beam-position adjustment — defining clinical differentiator versus gating-only systems.
  • Frameless cranial SRS at clinical quality — repeatedly demonstrated in literature.

Market position

Specialty SRS / SBRT platform. Strongest fit for frameless cranial SRS, prostate SBRT, and lung / spine SBRT with significant motion. Direct competitors:

Refurb posture

  • G4 / VSI legacy is value-tier refurb; M6 carries premium for the InCise MLC.
  • S7 refurb supply is small as installed base is younger.
  • Synchrony / Xsight licensing tier is the price-determining variable.

Related