Z-0485-2021Class II

MEVION S250i, MEVION S250; Proton Radiation Treatment System -

Name: Z-0485-2021 MEVION S250i, MEVION S250; Proton Radiation Treatment System -
Creator: Mevion Medical Systems, Inc.
Published: 2020-10-19
License: https://open.fda.gov/license/

Mevion Medical Systems, Inc. / initiated 2020-10-19 / Terminated / root cause: design

FDA source

Mevion Medical Systems, Inc. began a recall of MEVION S250i, MEVION S250; Proton Radiation Treatment System - Product Usage: intended to deliver proton radiation treatment to patients with localized tumors... on 2020-10-19. FDA classified it as Class II and gives the reason as "Treatment beam information disappears on Treatment Console screen while beam delivery continues potential for harm to a patient could occur". As of 2026-09-10, the recall status on record is Terminated, and MDM tags the root cause as design.

Recall record

Recall number: Z-0485-2021
Classification: Class II
Status: Terminated
Initiated: 2020-10-19
Posted: 2020-11-24
Terminated: 2021-08-31
Recalling firm: Mevion Medical Systems, Inc.
Product: MEVION S250i, MEVION S250; Proton Radiation Treatment System - Product Usage: intended to deliver proton radiation treatment to patients with localized tumors or any other conditions susceptible to treatment by radiation
Product code: LHN System, Radiation Therapy, Charged-Particle, Medical
Reason for recall: Treatment beam information disappears on Treatment Console screen while beam delivery continues potential for harm to a patient could occur
Root cause tag: design
FDA root cause: Device Design
Action: Mevion issued User Notice by mail or FedEx, with return receipt confirmation on October 22, 2020. The letter states reason for recall, health risk and action to take: The User should actively monitor the TC screen during beam delivery. In the event the TC screen beam information appears blank during Beam On, the user should: Immediately suspend treatment by selecting Beam Off on the Beam Control Box. Record the MU counts displayed on the HMUC before any other action is taken. Consult physics to make manual adjustments of the plan. Notify Field Service to retrieve machine records of the partial beam delivery. Resumption of treatment requires Setup workflow to be repeated. Corrective Action All users should be notified of this scenario and the proper response. Please contact Mevion Customer service with any questions or concerns. Please distribute this notice to all users of the Mevion Medical Systems device at your organization who may be affected by this issue User confirmation of receipt shall also be received from each affected customer site. Customer Service Engineers are also permanently in working residence at customer sites and will ensure awareness of the issue.
Quantity in commerce: 8 units
Distribution: Worldwide distribution - US Nationwide distribution including in the states of DC, FL, MO, NJ, OK and the country of Netherlands.
Product codes and lots: Serial Numbers: MEVION S250-0001 MEVION S250-0002 MEVION S250-0003 MEVION S250-0004 MEVION S250-0005 MEVION S250-0006 MEVION S250-0007 MEVION S250-0008 UDI: 01)00864366000100 (11) 131209 (01)00864366000100 (11)150526 (01)00864366000100 (11)150113 (01)00864366000100 (11)150430 (01)00864366000100 (11)160127 (01)00864366000100 (11)160603 (01)00864366000124 (11) 180220 (01)00864366000124 (11) 181219

Enforcement reports

One row per recalled product line

FDA enforcement reports joined to recall event Z-0485-2021
Recall number	Class	Status	Voluntary or mandated	Report date	Classified
Z-0485-2021	Class II	Terminated	Voluntary: Firm initiated	2020-12-02	2020-11-24

Product code LHN

K172848Class IIMEVION S250i Proton Beam Radiation Therapy DeviceMevion Medical Systems / cleared 2017-12-27

MDM coverage of this record lists here, newest first.

About this record

Sourced from the FDA device recall database and the FDA enforcement reports, both ingested from openFDA. The recall record supplies the product, the reason and the product code; the enforcement report supplies the classification. The two datasets are exported by FDA on different days, and the date above is the older of the two, so nothing on this page is newer than it says.

MDM adds the root cause tag, derived from FDA’s own root cause text, and the cross-links to the product code, the clearances named on the record and MDM coverage. Where a recall has not been joined to an enforcement report, no classification is shown.

Data as of 2026-09-30, the FDA export date for this dataset. Page last changed 2026-09-05. View this recall on fda.gov (opens on fda.gov)