Z-0588-2015Class II

MEVION S250, used for proton radiation therapy

Name: Z-0588-2015 MEVION S250, used for proton radiation therapy
Creator: Mevion Medical Systems, Inc.
Published: 2014-11-10
License: https://open.fda.gov/license/

Mevion Medical Systems, Inc. / initiated 2014-11-10 / Terminated / root cause: software

FDA source

Mevion Medical Systems, Inc. began a recall of MEVION S250, used for proton radiation therapy on 2014-11-10. FDA classified it as Class II and gives the reason as "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 an incorrect dose...". 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-0588-2015
Classification: Class II
Status: Terminated
Initiated: 2014-11-10
Posted: 2014-12-12
Terminated: 2015-03-18
Recalling firm: Mevion Medical Systems, Inc.
Product: MEVION S250, used for proton radiation therapy.
Product code: LHN System, Radiation Therapy, Charged-Particle, Medical
Reason for recall: 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 an incorrect dose delivery of no more than 5%.
Root cause tag: software
FDA root cause: Software design
Action: Mevion Medical Systems sent an Important Safety Notice letter to the affected customer. The letter identified the affected product, problem and actions to be taken. A software update addressing the issue will be provided to the customer on or about December 5, 2014. For questions or concerns, email [email protected] or call 978-540-1555.
Quantity in commerce: 1
Distribution: US Distribution in the state of MO
Product codes and lots: Serial Number: S250-0001

Enforcement reports

One row per recalled product line

FDA enforcement reports joined to recall event Z-0588-2015
Recall number	Class	Status	Voluntary or mandated	Report date	Classified
Z-0588-2015	Class II	Terminated	Voluntary: Firm initiated	2014-12-17	2014-12-11

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)