# K120676: S-250 Proton Beam Radiation Therapy System

- Pathway: 510(k) (Traditional)
- Applicant: Mevion Medical Systems
- Decided: Jun 4, 2012 after 91 days
- Product code: LHN (System, Radiation Therapy, Charged-Particle, Medical)
- Device class: 2
- Regulation: 21 CFR 892.5050
- Recalls of this device: 12 (0 Class I)
- Data: FDA decisions to Oct 25, 2026; recalls to Oct 12, 2026

## Lineage
Longest line of descent: 5 generations back to K872369 (1988). 11 ancestors in all.
5 later devices descend from it; 2 cite it directly.
0 of 17 devices in its family (counting itself) have a Class I recall.

## Predicates on the family tree (from the FDA summary)
- K060695: Iba Proton Therapy System - Proteus 235, Ion Beam Applications S.A. (2006) Summary page 4.
- K053641: Iba Proton Therapy System-Proteus 235, Ion Beam Applications S.A. (2006) Summary page 4.
- K061913: Iba Proton Therapy System - Proteus 235, Ion Beam Applications S.A. (2006) Summary page 4.
- K983332: Northeast Proton Therapy Center, Massachusetts General Hospital (2001) Summary page 4.
- K983024: Proton Therapy System, Ion Beam Applications S.A. (2001) Summary page 4.
- K872369: Loma Linda Univ. Proton Beam Therapy System, Loma Linda University Medical Center (1988) Summary page 4.
- K062891: Proton Therapy System, Indiana University Cyclotron Facility (2006) Summary page 4.
- K053280: Probeat, Hitachi, Ltd., Power Systems Group (2006) Summary page 4.
- K101294: PT2 Varian Proton Therapy System, Varian Medical Systems, Oncology Systems (2010) Summary page 4.
- (no number) Harvard Cyclotron: named in the summary without a submission number

## Most influential descendants
- K152224: Proton Therapy System - Proteus 235 (Proteus One, Proteus Plus, Proteus TK2) (2016), 4 descendants of its own
- K172848: MEVION S250i Proton Beam Radiation Therapy Device (2017), 2 descendants of its own
- K250986: S250-FIT Proton Beam Radiation Therapy Device (S250-FIT) (2025), 1 descendant of its own
- K253406: S250-FIT Proton Beam Radiation Therapy Device (S250-FIT) (2026), 0 descendants of its own
- K163500: IBA Proton Therapy System- Proteus 235 (Proteus One, Proteus Plus, Proteus TK2, Proteus Class) (2017), 0 descendants of its own

## Recalls of this device
- Feb 1, 2022 · Class II · Z-0827-2022: Malfunction of the hand pendant controlling movement of the therapy couch and nozzle may result in unintentional motion. Patient injury is possible if they come in contact with the nozzle or other obj
- Jun 23, 2020 · Class II · Z-2686-2020: The perforated screen that divides the inside of the process water tank has a very sharp edge across the top of the Heat Exchanger leading to potential injury for servicer.
- May 15, 2020 · Class II · Z-2406-2020: Couch Correction moves sent after using a 3D CT scan are partially lost if the previous correction sent or recorded had some of the Couch Correction checkboxes turned off
- Jun 29, 2018 · Class II · Z-2746-2018: QFix has advised Mevion Medical Systems that they are identifying unauthorized combinations of QFix Couch Tops with non-QFix devices in clinical use. The kVue Oen Touch latch consists of a precision l
- Dec 16, 2016 · Class II · Z-1122-2017: An error can occur causing Delta corrections to be lost when one setup field is closed and another is opened
- Oct 31, 2016 · Class II · Z-0409-2017: Completing Setup Without Program Move Complete Can Cause An Isocenter Error
- Oct 21, 2016 · Class II · Z-0410-2017: Recovery of Incorrect Isocenter -operational change
- Oct 20, 2016 · Class II · Z-0411-2017: Software defect:2D projection of contours in Verity. The defect causes structures to appear off from their true position in the DRR and the radiograph with an error that increases with the distance of
- Mar 15, 2016 · Class II · Z-1529-2016: Possibility of Gantry Motion with Aperture or Compensator only partially inserted. An Aperture may fall out during Gantry motion. It is possible that it can hit a patient and cause traumatic injury or
- Nov 18, 2015 · Class II · Z-0767-2016: The treatment table positioning belt can slip gear positions, resulting in deviation of patient setup and treatment positions from the time of slippage until the discovery of slippage and the halting 
- Nov 10, 2014 · Class II · Z-0588-2015: Software defect that causes an incorrect dose compensation function to be applied to the internal dose ionization chamber when either pressure or temperature sensor malfunction. This could result in a
- Mar 5, 2014 · Class II · Z-1271-2014: Geometric positioning error can occur after a rotational correction has been applied to one or more treatment fields

## Indications for use
The S-250 is intended to deliver proton radiation treatment to patients with localized tumors or any other conditions susceptible to treatment by radiation. The S-250 is a medical device indicated for the delivery of radiation for the treatment of patients with localized tumors or other conditions susceptible to treatment by radiation.

Source page: https://510kreport.com/device/K120676
Methodology: https://510kreport.com/methodology