Cleared Traditional

K250986 - S250-FIT Proton Beam Radiation Therapy Device (S250-FIT) (FDA 510(k) Clearance)

Class II Radiology device cleared through predicate-based substantial equivalence - typically does not require clinical trials.

K250986 · Mevion Medical Systems, Inc. · Radiology device
Download Printable Device Report (PDF)
Optimized for regulatory review, auditing and printing
Sep 2025
Decision
165d
Days
Class 2
Risk

K250986 is an FDA 510(k) clearance for the S250-FIT Proton Beam Radiation Therapy Device (S250-FIT). Classified as System, Radiation Therapy, Charged-particle, Medical (product code LHN), Class II - Special Controls.

Submitted by Mevion Medical Systems, Inc. (Littleton, US). The FDA issued a Cleared decision on September 12, 2025 after a review of 165 days - an extended review cycle.

This device falls under the Radiology FDA review panel, regulated under 21 CFR 892.5050 - the FDA radiology and imaging software oversight framework. The Traditional 510(k) pathway establishes clearance through substantial equivalence to a legally marketed predicate device, without requiring clinical trial data.

Device pattern: Standard predicate-based submission. Standard predicate reliance. This clearance follows a standard predicate-based equivalence path within the Radiology review framework, consistent with the majority of Class II 510(k) submissions.

View all Mevion Medical Systems, Inc. devices

Submission Details

510(k) Number K250986 FDA.gov
FDA Decision Cleared Substantially Equivalent - Traditional 510(k) (SESE)
Date Received March 31, 2025
Decision Date September 12, 2025
Days to Decision 165 days
Submission Type Traditional
Review Panel Radiology (RA)
Summary Summary PDF
Third-party Review No - reviewed directly by FDA
Combination Product No
PCCP Authorized No
Regulatory Context
Review time vs. panel average
58d slower than avg
Panel avg: 107d · This submission: 165d
Pathway characteristics
Predicate-based equivalence. No clinical trials required.

Device Classification

Product Code LHN System, Radiation Therapy, Charged-particle, Medical
Device Class Class 2 - Special Controls
CFR Regulation 21 CFR 892.5050
What this classification means

Class II devices require demonstration of substantial equivalence to a legally marketed predicate device. This pathway does not require clinical trials - it relies on engineering equivalence and performance data. Most Radiology devices follow this clearance model.

Regulatory Peers - LHN System, Radiation Therapy, Charged-particle, Medical

All 90
Devices cleared under the same product code (LHN) and FDA review panel - the closest regulatory comparables to K250986.
ProBeam 360 Proton Therapy System v3.0
K252815 · Varian Medical Systems, Inc. · Apr 2026
S250-FIT Proton Beam Radiation Therapy Device (S250-FIT)
K253406 · Mevion Medical Systems, Inc. · Mar 2026
eMotus Respiratory Motion Management System
K243900 · Empnia, Inc. · Jun 2025
P-Cure Proton Therapy System (PPTS)
K242418 · P-Cure, Ltd. · May 2025
PROBEAT-FR
K232032 · Hitachi, Ltd. Radiation Oncology Systems, Kashiwanoha · Jan 2024
ProBeam 360° Proton Therapy System v2.0 (Multiroom)
K231863 · Varian Medical Systems, Inc. · Oct 2023