system-familyAccurayTomotherapy

Accuray TomoTherapy (family)

Helical IMRT linac — 6 MV linear accelerator rotates continuously in a CT-like ring gantry around the patient while the couch translates through the bore, delivering modulated-intensity radiation in a helical fashion. Originated at the University of Wisconsin, commercialized as TomoTherapy Hi-Art in 2003, and acquired by Accuray in 2011. Modernized as the current-generation Radixact.

History

  • 2003 — TomoTherapy Hi-Art ships from TomoTherapy Inc., commercializing the Wisconsin helical-RT concept.
  • 2011 — Accuray acquires TomoTherapy Inc., bringing the helical platform into the Accuray oncology lineup alongside CyberKnife.
  • 2017 — Radixact launches as the Hi-Art successor with current-generation control / imaging stack.
  • 2020s — Synchrony for Radixact adds real-time tracking; ClearRT helical kV imaging on Radixact extends IGRT capability beyond MVCT.

Variants

  • TomoTherapy Hi-Art — original platform; large refurb / installed base in academic and tertiary cancer centers.
  • Radixact — current generation; faster, Synchrony tracking integration, ClearRT kV imaging.

Shared platform characteristics

  • 6 MV FFF linac in a CT-like ring gantry — 85 cm bore, 360° continuous rotation.
  • Binary MLC (64-leaf, fully in / fully out) — modulation achieved by rapid leaf-motion switching during rotation.
  • Megavoltage CT (MVCT) imaging for daily IGRT (Hi-Art baseline; Radixact also offers ClearRT kV CBCT).
  • Continuous couch translation — the helical-delivery architectural distinction from C-arm linacs.
  • Long-field / craniospinal / total-marrow delivery without field-junction matching.

Distinctive technology

  • Helical delivery — the architectural distinction from C-arm linacs. Particularly favorable for craniospinal irradiation (entire neuroaxis in one continuous target), total-marrow / total-lymphoid irradiation, and head-and-neck adjuvant work.
  • Binary MLC — high-speed leaf switching enables sub-second modulation per gantry-rotation slice.
  • Synchrony for Radixact — real-time tracking on the helical platform, extending the CyberKnife motion-management approach.

Market position

Specialty platform — not a volume competitor to C-arm IMRT / VMAT for routine fractionation. Strongest fit for long-target geometries (craniospinal, total-marrow, head-and-neck adjuvant) where helical delivery materially simplifies planning.

Direct competitors and adjacent platforms:

Refurb posture

  • Hi-Art legacy installed base is the value-tier refurb category — parts ecosystem mature; software / control-chassis support is the constraining factor.
  • Radixact refurb is too-young for meaningful secondary-market activity.
  • Synchrony for Radixact licensing is the price-determining variable on current-generation deals.

Related