# K253406: S250-FIT Proton Beam Radiation Therapy Device (S250-FIT)

- Pathway: 510(k) (Traditional)
- Applicant: Mevion Medical Systems, Inc.
- Decided: Mar 25, 2026 after 176 days
- Product code: LHN (System, Radiation Therapy, Charged-Particle, Medical)
- Device class: 2
- Regulation: 21 CFR 892.5050
- Recalls of this device: none
- Data: FDA decisions to Oct 25, 2026; recalls to Oct 12, 2026

## Lineage
Longest line of descent: 9 generations back to K872369 (1988). 17 ancestors in all.
No later device cites it as a predicate yet.
0 of 18 devices in its family (counting itself) have a Class I recall.

## Predicates on the family tree (from the FDA summary)
- K250986: S250-FIT Proton Beam Radiation Therapy Device (S250-FIT), Mevion Medical Systems, Inc. (2025) Summary page 5.

## Indications for use
The MEVION S250-FIT is intended to deliver proton radiation treatment to patients with localized tumors or any other conditions susceptible to treatment by radiation. When the patient is in the fully seated position, the MEVION S250-FIT is indicated for treatment of patients with localized tumors and other conditions susceptible to treatment by radiation in the sites above the mid-chest or carina.

Source page: https://510kreport.com/device/K253406
Methodology: https://510kreport.com/methodology