510(k) Report

510(k) · Cleared

Cleared

S250-FIT Proton Beam Radiation Therapy Device (S250-FIT)

K253406510(k) TraditionalCleared Mar 25, 2026176-day reviewClass II21 CFR 892.5050

Data to Oct 25, 2026 (FDA decisions) Oct 12, 2026 (recalls) Sep 30, 2026 (MAUDE) refreshed weekly, last Nov 3, 2026

Mevion Medical Systems, Inc. · LHN System, Radiation Therapy, Charged-Particle, Medical

Cleared on Mar 25, 2026 as substantially equivalent to K250986 (Mevion Medical Systems, Inc., 2025) after a 176-day review. Its family tree reaches back 9 generations to 1988.

Decided
Mar 25, 2026
Review
176 days
Class
Class II
Product code
LHN
Recalls
None
Predicates
1

Its longest line of descent runs back 9 generations to K872369 (1988). 17 ancestors in all. No later device cites it as a predicate yet.

  1. Root · 9 generations backK872369 Loma Linda Univ. Proton Beam Therapy SystemLoma Linda University Medical Center · 1988
  2. 5 generations between
  3. 3 generations backK152224 Proton Therapy System - Proteus 235 (Proteus One, Proteus Plus…Ion Beam Application S.A. · 2016 · Recalled
  4. 2 generations backK172848 MEVION S250i Proton Beam Radiation Therapy DeviceMevion Medical Systems · 2017 · Recalled
  5. 1 generation backK250986 S250-FIT Proton Beam Radiation Therapy Device (S250-FIT)Mevion Medical Systems, Inc. · 2025
  6. This deviceK253406 S250-FIT Proton Beam Radiation Therapy Device (S250-FIT)Mevion Medical Systems, Inc. · 2026
Show all 9 generations
  1. Root · 9 generations backK872369 Loma Linda Univ. Proton Beam Therapy SystemLoma Linda University Medical Center · 1988
  2. 8 generations backK983024 Proton Therapy SystemIon Beam Applications S.A. · 2001
  3. 7 generations backK053641 Iba Proton Therapy System-Proteus 235Ion Beam Applications S.A. · 2006
  4. 6 generations backK060695 Iba Proton Therapy System - Proteus 235Ion Beam Applications S.A. · 2006 · Recalled
  5. 5 generations backK062891 Proton Therapy SystemIndiana University Cyclotron Facility · 2006
  6. 4 generations backK120676 S-250 Proton Beam Radiation Therapy SystemMevion Medical Systems · 2012 · Recalled
  7. 3 generations backK152224 Proton Therapy System - Proteus 235 (Proteus One, Proteus Plus…Ion Beam Application S.A. · 2016 · Recalled
  8. 2 generations backK172848 MEVION S250i Proton Beam Radiation Therapy DeviceMevion Medical Systems · 2017 · Recalled
  9. 1 generation backK250986 S250-FIT Proton Beam Radiation Therapy Device (S250-FIT)Mevion Medical Systems, Inc. · 2025
  10. This deviceK253406 S250-FIT Proton Beam Radiation Therapy Device (S250-FIT)Mevion Medical Systems, Inc. · 2026
View FIG. 1 as a table

Line of descent and top descendants

GenerationNumberDeviceApplicantDecidedRecalls
−9K872369Loma Linda Univ. Proton Beam Therapy SystemLoma Linda University Medical Center1988—
−8K983024Proton Therapy SystemIon Beam Applications S.A.2001—
−7K053641Iba Proton Therapy System-Proteus 235Ion Beam Applications S.A.2006—
−6K060695Iba Proton Therapy System - Proteus 235Ion Beam Applications S.A.20062
−5K062891Proton Therapy SystemIndiana University Cyclotron Facility2006—
−4K120676S-250 Proton Beam Radiation Therapy SystemMevion Medical Systems201212
−3K152224Proton Therapy System - Proteus 235 (Proteus One, Proteus Plus, Proteus TK2)Ion Beam Application S.A.20167
−2K172848MEVION S250i Proton Beam Radiation Therapy DeviceMevion Medical Systems20175
−1K250986S250-FIT Proton Beam Radiation Therapy Device (S250-FIT)Mevion Medical Systems, Inc.2025—
0 (this device)K253406S250-FIT Proton Beam Radiation Therapy Device (S250-FIT)Mevion Medical Systems, Inc.2026—

Other ancestors by year cleared

Year clearedDevicesWith a Class I recall
200010
200110
200620
200810
201020
201410
FIG. 1 — Lineage of K253406, 1988–2026Source: FDA 510(k) summaries, read by 510(k) Report · How lineage is built

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Notable FDA decisions, review times and new Class I recalls. See an issue.

Sources: FDA 510(k) database (decision fields), the FDA summary (predicates and indications), FDA recall and enforcement reports, and MAUDE; processed by 510(k) Report. Verify on FDA.gov · Methodology and accuracy.

Planning a device in LHN? A 510(k) Report weighs predicate choices, recall history and review times for a new device like this one.

Top candidate predicates for a new LHN device

  1. #1 K260597 Virtue QAscore 15.4 · 12 generations · no Class I recall
  2. #2 Held for the reportin the report
  3. #3 Held for the reportin the report
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What was it cleared against? (1)

Devices the submitter claimed this one is substantially equivalent to (*), and reference devices cited for a specific test or feature (†), as written in the FDA summary.

TypeNumberDeviceApplicantDecidedRecalls
*K250986S250-FIT Proton Beam Radiation Therapy Device (S250-FIT)
Summary page 5
…rged-Particle, Medical Regulation Number: 892.5050 Product Code: LHN III. Predicate Device Predicate Device: S250-FIT Proton Beam Radiation Therapy Device (K250986) Regulation Number: 892.5050 Product Code: LHN…
Mevion Medical Systems, Inc.2025—

What descends from it?

No later submission names this one as a predicate yet.

Has anything in its family been recalled? (0 Class I)

No FDA recall names this device.

No ancestor or descendant has a Class I recall.

What does this lineage say?

  • The line of descent spans 38 years and passes through 6 companies; a new generation was cleared every 4.2 years on median.
  • 8 of the 17 ancestors have a recall of any class.

How does its category compare?

All LHN devices

LHN System, Radiation Therapy, Charged-Particle, Medical: FDA decisions, review times, recalls and adverse event reports over 20 years. 2026, this device’s year, is highlighted.

FDA decisions per year · LHN

3in 2025

2007: 22008: 32009: 52010: 42011: 12012: 32013: 32014: 42015: 32016: 72017: 42018: 32019: 22020: 42022: 22023: 22024: 12025: 32026 (partial year): 4
2007high 7 (2016) · low 0 (2021)2026

2026 to Oct 25, outlined.

Median 510(k) review, days · LHN

190in 2025

2008: 113 days median2009: 69 days median2010: 96 days median2012: 111 days median2013: 70 days median2014: 93 days median2015: 53 days median2016: 120 days median2017: 173 days median2018: 78 days median2020: 74 days median2025: 190 days median2026 (partial year): 194 days median
2007high 194 (2026) · low 53 (2015)2026

Receipt to decision; years with fewer than 3 clearances left blank.

Recalls per year · LHN

1in 2023

2007: 22008: 22014: 22015: 12017: 52018: 22020: 12021: 12022: 22023: 1
2007high 5 (2017) · low 0 (2009)2026

Class I (0 since 2007) Class II/III not classified

Adverse event reports per year · LHN

11in 2025

2008: 12009: 52010: 32011: 12012: 12013: 12014: 52015: 22016: 12017: 72018: 82019: 32020: 202021: 242022: 102023: 72024: 22025: 11
2007high 24 (2021) · low 0 (2007)2025

MAUDE reports naming product code LHN, not matched to any one device; reports are not rates.

View these four charts as a table
YearDecisionsMedian 510(k) review, daysRecalls (Class I)MAUDE reports
20072—20
2008311321
200956905
201049603
20111—01
2012311101
201337001
201449325
201535312
2016712001
2017417357
201837828
20192—03
2020474120
20210—124
20222—210
20232—17
20241—02
20253190011
202641940—

What is it indicated for?

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.

Indications for use as stated in the FDA summary.

Cite this page

510(k) Report. “K253406: S250-FIT Proton Beam Radiation Therapy Device (S250-FIT).” Lineage record from FDA 510(k) data and the FDA summary. Updated Nov 3, 2026. Accessed Nov 5, 2026. https://510kreport.com/device/K253406

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Record history
  • FDA decision record loaded May 2, 2026
  • Summary read Oct 13, 2026 (extraction version 9eaa42aa01ed)
  • Lineage and recalls computed Nov 3, 2026
  • Page last updated Nov 3, 2026