MAUDE Adverse Event Report: MEVION MEDICAL SYSTEMS, INC.; MEVION S250I

Model Number	MEVION S250I
Medical Device Problem Code	Therapy Delivered to Incorrect Body Area (1508)
Health Effect - Clinical Code	No Clinical Signs, Symptoms or Conditions (4582)
Date of Event	01/12/2024
Type of Reportable Event	Serious Injury
Event or Problem Description
On friday january 12, the first beam of a 5-beam fraction was delivered to an incorrect position with errors of 3.4 cm in vertical, 9.3 cm in longitudinal and 6.9 cm in lateral, resulting in an overdose to surrounding tissue and an underdose to the target.This error was calculated to amount to a +/- 2.5% dose error (~1.5 gy) over the course of a single treatment.There was no adverse reaction to the patient reported by the facility.The root cause of the incorrect delivery was determined to be user error.
Additional Manufacturer Narrative
The misdelivery was a result of user error, as the alignment position corrections were inadvertently not applied by the user, despite this being a standard part of the workflow as described in the user manual.However, there was no significant dose increase to organs at risk and no significant underdose to the tumor and therefore no adjustments to the treatment were required to compensate for this error.Although, there was no evidence of immediate serious injury, an accidental radiation occurence did occur, attributed to user error at this facility in the netherlands.There are no other known instances of this occuring since the device was cleared in 2017.As the radiation dose could potentially lead to serious injury, mevion is reporting the incident to fda.

• Common Device Name: MEVION S250I
• Manufacturer (Section D): MEVION MEDICAL SYSTEMS, INC.; 300 foster street; littleton MA 01460
• Manufacturer (Section G): MEVION MEDICAL SYSTEMS, INC.; 300 foster street; littleton MA 01460
• Manufacturer Contact: ping hu ; 300 foster st; littleton, MA 01460 ; 9785401500
• MDR Report Key: 18625672
• Report Number: 3007087027-2024-00001
• Device Sequence Number: 8092964
• Product Code: LHN
• UDI-Device Identifier: 00864366000124
• UDI-Public: (01)00864366000124(11)181219
• Combination Product (Y/N): N
• Initial Reporter Country: NL
• PMA/510(K) Number: K172848
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Serviced by Third Party (Y/N): N
• Reporter Type: Manufacturer
• Report Source: Foreign,Health Professional,User Facility
• Initial Reporter Occupation: Other Health Care Professional
• Type of Report: Initial
• Report Date (Section B): 01/30/2024

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Is this an Adverse Event Report?: Yes
• Is this a Product Problem Report?: No
• Operator of Device: Health Professional
• Device Model Number: MEVION S250I
• Device Catalogue Number: N/A
• Device Lot Number: N/A
• Was Device Available for Evaluation?: Yes
• Is the Reporter a Health Professional?: Yes
• Type of Report(Section G): Thirty-Day
• Initial Date Received by Manufacturer: 01/12/2024
• Initial Report FDA Received Date: 02/01/2024
• Was Device Evaluated by Manufacturer? (Y/N): Device Not Returned to Manufacturer
• Date Device Manufactured: 12/19/2018
• Is the Device Labeled for Single Use? (Y/N): No
• Is This a Single-Use Device that was Reprocessed and Reused on a Patient? (Y/N): No
• Usage of Device: Initial
• Patient Sequence Number: 1
• Outcome Attributed to Adverse Event: Other
• Patient Sex: Unknown