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

Model Number	MEVION S250I
Medical Device Problem Codes	Application Network Problem (2879); Intermittent Communication Failure (4038)
Health Effect - Clinical Code	No Clinical Signs, Symptoms or Conditions (4582)
Date of Event	04/24/2024
Type of Reportable Event	Malfunction
Additional Manufacturer Narrative
While the patient plan was loading into the patient registration application ('verity'), communications between the registration application and the treatment delivery console were interrupted.Before the interruption, verity was only able to load approximately half of the planning ct slices and logged an error.Verity does not load the slices in a sequential order, and because of the communications disruption during the data transfer, this introduced gaps in the ct dataset.Verity interpolated to cover the missing slices, and this caused the generation of elongated contours.These elongated contours were then used to align the patient for treatment, leading to a misalignment.Communications between verity and the treatment delivery system were re-established while the patient was still loaded, causing these newly generated, elongated contours to be saved and also used for the subsequent delivery fraction.Clearing the cache of the incorrectly generated contours forced verity to regenerate contours, this time from a full ct data set.This resolved the issue for this patient's remaining delivery fractions.A software change will be implemented to have the system report an error if the data transfer is interrupted instead of trying to generate contours without the missing ct slices.A requirement for this will be added to the system requirements document, and this will be a new, additional mitigation in the subsystem hazard analysis.Mevion has also performed a logfile analysis and determined that an event such as this one has occured twice previously, but only ever on this particular machine.This particular machine has an open it ticket with the hospital's it staff to address ongoing data communications issues.
Event or Problem Description
During treatment of patient (b)(6) on (b)(6) 2024, therapists noted that contours looked elongated on patient images, but proceeded with alignment and treatment.Contours looked as expected (not elongated) in offline review.Patient (b)(6) was the only patient with this issue, no other patients on (b)(6) had this issue.When setting up this patient on (b)(6), therapists noted that contours were elongated again.After treating, the patient images were looked at in offline review and the contours once again appeared as expected.Therapists expressed concerns of a misalignment due to the elongated contours.Physician review of the records showed that two separate fractions were misaligned, fractions on both the 24th and 25th.The first fraction was misaligned by 0.72cm and 0.83cm, and the second fraction was misaligned by 1.3cm and 1.5cm.No harm or patient effects have been reported.

• 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 street; littleton, MA 01460 ; 9785401500
• MDR Report Key: 19370411
• Report Number: 3007087027-2024-00002
• Device Sequence Number: 7538024
• Product Code: LHN
• UDI-Device Identifier: 00864366000124
• UDI-Public: (01)00864366000124(11)230717
• Combination Product (Y/N): N
• Initial Reporter State: KS
• Initial Reporter Country: US
• 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: Health Professional,User Facility
• Initial Reporter Occupation: Other Health Care Professional
• Type of Report: Initial
• Report Date (Section B): 05/21/2024

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Is this an Adverse Event Report?: No
• Is this a Product Problem Report?: Yes
• 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: 04/25/2024
• Initial Report FDA Received Date: 05/22/2024
• Was Device Evaluated by Manufacturer? (Y/N): Yes
• Date Device Manufactured: 07/17/2023
• 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: Reuse
• Patient Sequence Number: 1
• Patient Sex: Unknown