Accuray Incorporated
Radiation-oncology specialist. Two distinct product families, both non-conventional linac architectures:
- CyberKnife — 6 MV compact linac mounted on a 6-axis industrial robotic arm; image-guided tracking via orthogonal kV imaging or fiducial-free Synchrony.
- TomoTherapy / Radixact — helical megavoltage delivery with integrated MVCT imaging.
Publicly listed on NASDAQ. Distinct from the Varian / Elekta C-arm linac duopoly — Accuray's value proposition is purpose-built geometry for clinical niches the C-arm class doesn't address as cleanly.
Company history
- 1990 — founded by Dr. John Adler (Stanford neurosurgeon). Goal: apply Leksell Gamma Knife-like stereotactic accuracy to the whole body, not only the brain.
- 1999 — first CyberKnife FDA clearance.
- 2007 — Accuray IPO on NASDAQ.
- 2011 — acquires TomoTherapy Inc. (TomoTherapy Hi-Art had shipped in 2003 under the separate company), unifying robotic and helical platforms under one OEM.
- 2017 — Radixact launches as the TomoTherapy successor with a current-generation control / imaging stack and the Synchrony for Radixact real-time tracking option.
- 2020s — ClearRT helical kV imaging on Radixact, ongoing CyberKnife S7 / M6 generation in active production.
Product line
- CyberKnife — S7 (current), M6 (widely deployed), VSI (legacy installed base).
- TomoTherapy / Radixact — Radixact (current), TomoTherapy Hi-Art (legacy).
- Accuray Precision — treatment-planning system unified across both platforms.
- iDMS — oncology information system / R&V.
Distinctive technology
- CyberKnife robotic delivery — the 6-DoF industrial robot positions the small linac through hundreds of non-coplanar beam directions per fraction, with continuous orthogonal-imaging-based tracking. Frameless cranial SRS and respiratory-tracked extracranial SBRT (lung, liver, prostate, pancreas).
- Synchrony tracking — fiducial-based or fiducial-free real-time tracking, with the robot adjusting position in response to target motion. The defining clinical differentiator on the platform.
- TomoTherapy helical delivery — patient translates continuously through the bore while a 6 MV ring-gantry linac rotates, sweeping a binary-MLC fan-beam IMRT pattern. Extremely conformal long-target treatments — craniospinal irradiation, head-and-neck adjuvant, total-marrow / total-lymphoid irradiation — without complex field-junction matching.
- MVCT integrated into the Tomo gantry — daily IGRT on the same hardware that delivers the beam.
Market position
Specialty player in radiation oncology. Not a volume competitor to Varian and Elekta in general external-beam radiotherapy, but holds meaningful share in:
- SRS / SBRT via CyberKnife — particularly cranial frameless SRS, prostate SBRT, and select pulmonary / hepatic SBRT programs.
- Long-target / craniospinal via TomoTherapy / Radixact — specialty geometries where helical delivery materially simplifies planning.
Competitors are platform-specific: CyberKnife competes against Varian Edge / TrueBeam STx, Elekta Versa HD, and Leksell Gamma Knife on cranial SRS; TomoTherapy / Radixact competes against C-arm linac VMAT.
Refurb posture
- CyberKnife installed base turns over slowly; refurb activity exists at S7 / M6 level but with strong service-contract dependence.
- TomoTherapy Hi-Art legacy units are still in service; parts ecosystem is mature but software / control-chassis support is the constraining factor.
- License tier — Synchrony for Radixact, MLC-class on Hi-Art, and tracking software entitlements are price-determining variables.