MAUDE Adverse Event Report: ELEKTA INC. MOSAIQ; ACCELERATOR, LINEAR, MEDICAL, PRODUCT CODE: IYE

Lot Number	VERSION 2.83.053
Medical Device Problem Code	Computer Software Problem (1112)
Health Effect - Clinical Code	Insufficient Information (4580)
Type of Reportable Event	Malfunction
Event or Problem Description
The customer reports that the same field was delivered twice.
Additional Manufacturer Narrative
The manufacturer's investigation is on-going and further information will be provided once the investigation has completed.H4: manufacturing date is not on the label, but it is known so field h4 has been completed with this information.
Additional Manufacturer Narrative
H6 updated.H11 updated: the customer reports that the same field was delivered twice.The investigation was completed by conducting a thorough evaluation of the products and the reported information.The audit log shows that on (b)(6) 2025, fields 1,2 & 3 were sent for treatment.Note that field 1 was a ct field, which is not a treatment field and is used for patient positioning.According to the log file, field 2 was not treated and field 3 was partially treated for 176mu out of 299mu, and recorded as such in mosaiq, leaving 123mu to be delivered.The fields were selected again and mosaiq displayed a warning that field 3 had already been treated within the last 4 hours.The fields were sent to the machine for treatment.There was a machine communications time out error and the session exited without treating or recording anything.The fields were selected again and mosaiq displayed a warning that field 3 had already been treated within the last 4 hours.The treatment session was terminated without treating or recording anything.A new treatment calendar session was selected with all 3 fields 1, 2 & 3 with their full mus for treatment.Mosaiq displayed a warning that field 3 had already been treated within the last 4 hours.An attempt was made to restore the fields, however there was nothing for them to restore to because you can only restore fields that have been used already.A complete partial on field 2 was performed, this was use error because field 2 had not yet been treated, and the 176mu delivered was from field 3, not field 2.Therefore field 2 with only 101mu of the intended 277mu was sent to the machine for treatment.In this session, field 2 was treated with 101mu and field 3 was treated with 299mu, and mosaiq recorded this correctly.Therefore field 2 was under treated by 176mu and field 3 was over treated by 176mu.Elekta physics have assessed this as an insignificant radiation underdose, over the course of the treatment.The customer has also performed an assessment of the incident and found that no change to the treatment course is necessary as a result of the incident.Mosaiq did not have any malfunction and was working as designed and intended.The root cause was use error.

• Brand Name: MOSAIQ
• Common Device Name: ACCELERATOR, LINEAR, MEDICAL, PRODUCT CODE: IYE
• Manufacturer (Section D): ELEKTA INC.; 100 mathilda place; 5th floor; sunnyvale CA 94086
• 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: 21322069
• Report Number: 2950347-2025-00008
• Device Sequence Number: 15485938
• Product Code: IYE
• UDI-Device Identifier: 00858164002367
• UDI-Public: (01)00858164002367(10)2.83.053
• Combination Product (Y/N): N
• Initial Reporter Country: NZ
• 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,Foreign,Health Professional,User Facility
• Initial Reporter Occupation: Administrator/Supervisor
• Type of Report: Initial,Followup
• Report Date (Section B): 08/05/2025

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 2.83.053
• Was Device Available for Evaluation?: Yes
• Type of Report(Section G): Thirty-Day
• Initial Date Received by Manufacturer: 01/07/2025
• Supplement Date Received by Manufacturer: Not provided
• Initial Report FDA Received Date: 02/06/2025
• Supplement Report FDA Received Date: 08/05/2025
• Was Device Evaluated by Manufacturer? (Y/N): Yes
• Date Device Manufactured: 08/31/2021
• 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