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

Lot Number	VERSION 2.83.053
Medical Device Problem Code	Computer Software Problem (1112)
Health Effect - Clinical Code	Insufficient Information (4580)
Date of Event	06/18/2025
Type of Reportable Event	Malfunction
Event or Problem Description
The customer reported a problem merging cbct into mosaiq.
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.
Additional Manufacturer Narrative
H6 updated.H11 updated: the investigation was completed by conducting a thorough evaluation of the product and the reported information.The customer reported a problem merging cbct into mosaiq.The customer replanned a new reference ct with a revised isocenter for a patient scheduled to be treated on two versa machines (versa 1 and versa 2).However, the updated isocenter was not applied on versa 2.As a result, the original isocenter was used for imaging and treatment on versa 2.On july 16, 17, 18, and 21, 2025, treatments on versa 1 used the new isocenter: x = 2.63; y = -24.24; z = -5.06.On (b)(6) 2025, treatments on versa 2 used the old isocenter: x = 2.24; y = -24.13; z = 1.60.The customer received warning messages regarding the discrepancy but proceeded with treatment.Consequently, the patient was treated using an incorrect setup on these dates.A reference setup image was not updated on versa 2, resulting in a setup mismatch on 10 treatment days.The exact dosimetric error cannot be reconstructed from available data but is estimated to range from several millimeters up to 5-6 cm.The customer reported no expected clinical consequences for the patient.Based on the information that was provided, mosaiq is working as intended.The actual mistreatment was due to use error and elekta physics assessed this as a non-serious radiation underdose.

• Brand Name: MOSAIQ
• Common Device Name: ACCELERATOR, LINEAR, MEDICAL
• Manufacturer (Section D): ELEKTA SOLUTIONS AB; hagaplan 4; stockholm, 113 6 8; SW 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: 22975543
• Report Number: 3015232217-2025-00055
• Device Sequence Number: 13109231
• Product Code: IYE
• UDI-Device Identifier: 00858164002367
• UDI-Public: (01)00858164002367(10)2.83.053
• Combination Product (Y/N): N
• Initial Reporter Country: FR
• 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: Other Health Care Professional
• Type of Report: Initial,Followup
• Report Date (Section B): 01/14/2026

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
• Is the Reporter a Health Professional?: Yes
• Type of Report(Section G): Thirty-Day
• Initial Date Received by Manufacturer: 08/08/2025
• Supplement Date Received by Manufacturer: Not provided
• Initial Report FDA Received Date: 09/05/2025
• Supplement Report FDA Received Date: 01/14/2026
• Was Device Evaluated by Manufacturer? (Y/N): Yes
• Date Device Manufactured: 08/31/2021
• 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