Z-1122-2017Class II

MEVION S250-Proton Radiation Therapy

Name: Z-1122-2017 MEVION S250-Proton Radiation Therapy
Creator: Mevion Medical Systems, Inc.
Published: 2016-12-16
License: https://open.fda.gov/license/

Mevion Medical Systems, Inc. / initiated 2016-12-16 / Terminated / root cause: software

FDA source

Mevion Medical Systems, Inc. began a recall of MEVION S250-Proton Radiation Therapy Product Usage: Proton Radiation Therapy on 2016-12-16. FDA classified it as Class II and gives the reason as "An error can occur causing Delta corrections to be lost when one setup field is closed and another is opened". As of 2026-09-10, the recall status on record is Terminated, and MDM tags the root cause as software.

Recall record

Recall number: Z-1122-2017
Classification: Class II
Status: Terminated
Initiated: 2016-12-16
Posted: 2017-02-02
Terminated: 2017-04-13
Recalling firm: Mevion Medical Systems, Inc.
Product: MEVION S250-Proton Radiation Therapy Product Usage: Proton Radiation Therapy
Product code: LHN System, Radiation Therapy, Charged-Particle, Medical
Reason for recall: An error can occur causing Delta corrections to be lost when one setup field is closed and another is opened
Root cause tag: software
FDA root cause: Software design
Action: Mevion sent an Important Safety Notice to customers on 12/16/16 by email and Salesforce. The letter identified the affected product, problem and actions to be taken. Mevion provided mitigation and will release and install a software patch that removes the possibility that Deltas can be lost between multiple Setup fields. For further information contact [email protected].
Quantity in commerce: 2 units
Distribution: US Nationwide in the states of OK, NJ
Product codes and lots: S250-0002 and S250-0003

Enforcement reports

One row per recalled product line

FDA enforcement reports joined to recall event Z-1122-2017
Recall number	Class	Status	Voluntary or mandated	Report date	Classified
Z-1122-2017	Class II	Terminated	Voluntary: Firm initiated	2017-02-08	2017-02-02

Product code LHN

K120676Class IIS-250 Proton Beam Radiation Therapy SystemMevion Medical Systems / cleared 2012-06-04

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)