MAUDE Adverse Event Report: ELEKTA SOLUTIONS AB MONACO; SYSTEM, PLANNING, RADIATION THERAPY TREATMENT

Lot Number	6.2.2.0
Medical Device Problem Codes	Application Program Problem: Parameter Calculation Error (1449); Insufficient Device Problem Information (3190)
Health Effect - Clinical Codes	Insufficient Information (4580); Appropriate Clinical Signs, Symptoms and Conditions Term/Code Not Available (4581)
Date of Event	08/07/2025
Type of Reportable Event	Malfunction
Event or Problem Description
The customer reported that the adapt setup mean ed for external contour is different for two identical study sets.
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 issue was determined to be a defect in the product.The customer reported that the adapt setup mean electron density (ed) for the external contour is different for two identical studysets.After re-contouring in an adaptive plan (in adapt setup tab), if the user switches a structure to or from the internal and external types, the average density is not recalculated to account for unspecified voxels (unspecified voxels are not included in contoured structures).As a result, a plan may be approved with incorrect average density values.The issue occurs when the user changes structure type.Monaco will not recalculate mean ed.If the structure is changed, then the average density should change.This could cause a problem because the average density could be incorrect.Ed calculation is only triggered by enabling the contouring tool.Based on available information there was no mistreatment.The defect that causes the density values not to be automatically re-calculated when a structure is switched type will be fixed in a future release.The mean ed column values are intended as suggestions only.It is the user's responsibility to review ed values as only the user can determine if they are acceptable for use in a specific clinical situation.The relevant warnings are covered in the instructions for use: warning 1.1.All plans must be validated for correctness, including a secondary monitor unit check, by qualified personnel before clinical use.

• Brand Name: MONACO
• Common Device Name: SYSTEM, PLANNING, RADIATION THERAPY TREATMENT
• Manufacturer (Section D): ELEKTA SOLUTIONS AB; hagaplan 4; stockholm, 113 6 8; SW 113 68
• Manufacturer (Section G): ELEKTA SOLUTIONS AB; hagaplan 4; stockholm, 113 6 8; SW 113 68
• Manufacturer Contact: cornerstone; london road; crawley, west sussex RH10 -9BL
• MDR Report Key: 22976758
• Report Number: 3015232217-2025-00057
• Device Sequence Number: 18377113
• Product Code: MUJ
• UDI-Device Identifier: 07340201500064
• UDI-Public: (01)07340201500064(10)6.2.2.0
• Combination Product (Y/N): N
• Initial Reporter State: WI
• Initial Reporter Country: US
• PMA/510(K) Number: K223233
• 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): 01/06/2026

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: 6.2.2.0
• 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: 08/07/2025
• Supplement Date Received by Manufacturer: Not provided
• Initial Report FDA Received Date: 09/05/2025
• Supplement Report FDA Received Date: 01/06/2026
• Was Device Evaluated by Manufacturer? (Y/N): Yes
• Date Device Manufactured: 06/06/2024
• 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