Mevion S250 (family)
Modality: Proton Therapy
Mevion's compact single-room proton-therapy system — established the U.S. community-hospital proton-therapy category alongside IBA Proteus ONE. Architecturally distinct: superconducting synchrocyclotron mounted directly on the gantry, eliminating the separate cyclotron vault and beam-transport infrastructure of multi-room proton centers.
Variants
- S250 — original 2013-era platform; first clinical install at Barnes-Jewish Hospital (St. Louis).
- S250i — refresh generation.
- S250-FIT — current, with HYPERSCAN pencil-beam scanning.
Distinctive technology
- Gantry-mounted superconducting synchrocyclotron — compact accelerator integrated with the rotating gantry; the architectural innovation that made single-room community-hospital proton therapy economically viable.
- HYPERSCAN pencil-beam scanning (S250-FIT) — modulated-spot delivery with rapid energy switching; the modern PBS standard delivered on the compact platform.
- Adaptive Aperture — collimating element on selected configurations.
- Single-room footprint — building / shielding requirements substantially smaller than multi-room proton centers.
Clinical use
- Pediatric oncology — dose-sparing for CNS tumors, sarcomas, retinoblastoma, leukemia / lymphoma adjuvant.
- Base-of-skull and CNS — chordoma, chondrosarcoma, optic pathway tumors.
- Selected adult indications — base-of-skull, re-irradiation, eye / orbit, pediatric and AYA cancers.
Refurb posture
- No meaningful refurb market — installed base small and per-vendor; lifecycle decisions are program-level events.
- Service-contract continuity dominates operating economics.
- Pre-HYPERSCAN S250 / S250i legacy installs face evolving service-support timelines; programs evaluate explicitly.