MAUDE Adverse Event Report: ELEKTA SOLUTIONS AB MOSAIQ; ACCELERATOR, LINEAR, MEDICAL

Lot Number	VERSION 2.86.054
Medical Device Problem Code	Computer Software Problem (1112)
Health Effect - Clinical Code	Insufficient Information (4580)
Date of Event	06/03/2025
Type of Reportable Event	Malfunction
Additional Manufacturer Narrative
H4: manufacturing date is not on the label, but it is known so field h4 has been completed with this information.The manufacturer's investigation is on-going and further information will be provided once the investigation has completed.
Event or Problem Description
The customer reported that a treatment field did not record.
Additional Manufacturer Narrative
H2 updated.H6 updated.H11 updated: the investigation was completed by conducting a thorough evaluation of the product and the reported information.The customer reported that a treatment field did not record.The customer informed that they received the following message upon closing the patient chart on the sequencer machine "projected rx mismatches: for all fields treated in this session, fractional dose mismatches are listed below.Continue? "rx site - left breast, fx - 12, rx - 266 cgy, actual - 131 cgy, projected - mismatch by 135cgy, tolerance - 1 cgy".It was confirmed from the machine logs that on (b)(6) 2025 at 09:59:19 am, treatment fields were sent to the machine.During this session, all fields were fully treated and correctly recorded in mosaiq.At 10:05:06 am further fields were sent to the machine for treatment.However, mosaiq only received a beam record for field 3a during this session.There was no indication that field 4a was treated in the session or for the rest of the day.The reason the customer received the warning message upon closing the patient chart was because the dose expected for rx site: left breast, was 266cgy which is the total dose for treating both fields 3a & 4a, as field 4a was not treated on (b)(6) 2025 the dose was not counted towards the total dose.From the machine logs elekta can see that the customer was prompted with the mosaiq message "all fields were not treated warning" along with the actual dose accounted for the session message.The warning message that the customer saw confirms the dose mismatch.It was found that the session/fraction on (b)(6) 2025 was under-treated.As this also relates to a third-party product (varian), it is recommended that the customer check with varian to confirm that the field was indeed treated for the patient on (b)(6) 2025.Mosaiq did not have any malfunction and was working as designed and intended.The findings of our investigation have been formally communicated to the customer via email.

• Brand Name: MOSAIQ
• Common Device Name: ACCELERATOR, LINEAR, MEDICAL
• Manufacturer (Section D): ELEKTA SOLUTIONS AB; hagaplan 4; stockholm, SE-11 3 68; SW SE-113 68
• Manufacturer (Section G): ELEKTA SOLUTIONS AB; 400 perimeter center terrace; suite 50; atlanta GA 30346
• Manufacturer Contact: cornerstone; london road; crawley, west sussex RH10 -9BL
• MDR Report Key: 22394442
• Report Number: 3015232217-2025-00046
• Device Sequence Number: 18418174
• Product Code: IYE
• UDI-Device Identifier: 00858164002367
• UDI-Public: (01)00858164002367(10)2.86.054
• Combination Product (Y/N): N
• Initial Reporter State: MD
• Initial Reporter Country: US
• PMA/510(K) Number: K183034
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Serviced by Third Party (Y/N): Unknown
• Reporter Type: Manufacturer
• Report Source: Other,User Facility
• Initial Reporter Occupation: Other Health Care Professional
• Type of Report: Initial,Followup
• Report Date (Section B): 10/03/2025

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?: No
• Operator of Device: Health Professional
• Device Lot Number: VERSION 2.86.054
• 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: 06/03/2025
• Supplement Date Received by Manufacturer: Not provided
• Initial Report FDA Received Date: 07/03/2025
• Supplement Report FDA Received Date: 10/03/2025
• Was Device Evaluated by Manufacturer? (Y/N): Yes
• Date Device Manufactured: 06/07/2023
• 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