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

Lot Number	VERSION 2.84.002
Medical Device Problem Code	Computer Software Problem (1112)
Health Effect - Clinical Code	Insufficient Information (4580)
Date of Event	12/22/2025
Type of Reportable Event	Malfunction
Additional Manufacturer Narrative
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 mosaiq recorded a session incorrectly.
Additional Manufacturer Narrative
H11: updated: the customer reported that mosaiq recorded a session incorrectly.The investigation was completed by conducting a thorough evaluation of the product and the reported information.On (b)(6) 2025, field 1.1 was entered for treatment at 10:20:25.Treatment stopped when a "beam mu ch1" error occurred on the machine at 10:25.Mosaiq received a count of 2005.7 mu from the machine as having been delivered which matches the prescribed 2005.7 mu processed and recorded by mosaiq.The data received by mosaiq for recording this delivery shows an unusual jump in mu reported by the linac from 1,277.5 mu to 2,005.7 mu (segment 199 to segment 200) when treatment ended.The customer explains that a power outage occurred while treating field 1.1 and only 1281 mu had been given up to that point.The sdd logs are necessary to determine why the linac reported 2005.7 mu to mosaiq instead of 1281 mu.Unfortunately, the sdd logs covering the event are not available for review because they are periodically overwritten.The customer has already made chart corrections to show that 1281 mu of the prescribed 2005.7 mu was given.Field 1.1 was underdosed by 724.7 mu.Elekta physics have assessed that, in the worst case where the underdose is not corrected, this would be an insignificant radiation overdose.Mosaiq is working as intended.

• Brand Name: MOSAIQ
• Common Device Name: ACCELERATOR, LINEAR, MEDICAL, PRODUCT CODE: IYE
• Manufacturer (Section D): ELEKTA SOLUTIONS AB; hagaplan 4; stockholm, 113 6 8,; SW 113 68,
• Manufacturer (Section G): ELEKTA SOLUTIONS AB; hagaplan 4; suite 50; stockholm, GA 113 6 8; SW 113 68
• Manufacturer Contact: cornerstone; london road; crawley, west sussex RH10 -9BL
• MDR Report Key: 24207126
• Report Number: 3015232217-2026-00002
• Device Sequence Number: 5495502
• Product Code: IYE
• UDI-Device Identifier: 00858164002367
• UDI-Public: (01)00858164002367(10)2.84.002
• Combination Product (Y/N): N
• Initial Reporter Country: SP
• 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): 03/09/2026

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 Lot Number: VERSION 2.84.002
• 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: 12/31/2025
• Supplement Date Received by Manufacturer: Not provided
• Initial Report FDA Received Date: 01/29/2026
• Supplement Report FDA Received Date: 03/09/2026
• Was Device Evaluated by Manufacturer? (Y/N): Yes
• Date Device Manufactured: 03/07/2022
• 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