MAUDE Adverse Event Report: ELEKTA LTD PRECISE SERIES LINAC; ACCELERATOR, LINEAR, MEDICAL

Model Number 151255

Device Problem Device Operates Differently Than Expected (2913)

Patient Problem No Code Available (3191)

Event Type  Injury  

Event Description

The customer reported that there was a field treated with an incorrect couch rotation.

Manufacturer Narrative

A patient's treatment had a prescribed table iso of 350 degrees.The users failed to rotate the table manually or via asu to the prescribed position.Mosaiq warned the user that both the table longitudinal and iso were out of tolerance, but these warnings were overridden by the user.The hospital has stated that overrides are common, particularly longitudinal, when moving a patient from one machine to another.In addition, they had customised the linac tolerances to allow a table iso error of up to 10 degrees; the default value is 1 degree.This was done on the basis that the mosaiq iso tolerance was set to 1 degree.The likelihood of this event leading to a clinical mistreatment has been judged to be improbable based on the following conditions:- in order for the treatment to proceed the linac tolerances must be increased from the default; in this case the hospital increased them from 1 degree to 10 degrees.There is a warning in the manual regarding changes to tolerance tables: (b)(4).The potential severity of a mistreatment that was 10 degrees away from the prescribed position has been judged to be major.This gives a risk value of major x improbable = tolerable.No information was available from the customer regarding the clinical consequences of patient mistreatment.The manufacturer's investigation is ongoing.

Manufacturer Narrative

The manufacturer's final investigation found that the linac tolerances had been customized by the user to allow a table iso error of up to 10 degrees; the default value being 1 degree which matches the mosaiq table iso tolerance.The user then subsequently failed to rotate the table manually or via asu to the prescribed position.Mosaiq warned the customer that both the table longitudinal and iso were out of tolerance, but these warnings were overridden by the user.The hospital has stated that some overrides are common, particularly longitudinal, when moving a patient from one machine to another.Overriding of the important table out of tolerances could potentially lead to major mistreatment.The customer has been informed about this issue and requested to tighten the tolerances.They have also been requested to arrange a visit with the manufacturer's field service engineers to investigate the reason behind why they are getting so many inhibits, as this is believed to be part of the reason as to why this was overridden.The manufacturer was not aware of any similar incidents with a similar root cause, however they are analysing the impact of implementing changes to the software that could limit or remove the functionality of override inhibits on table iso positioning.

• Brand Name: PRECISE SERIES LINAC
• Type of Device: ACCELERATOR, LINEAR, MEDICAL
• Manufacturer (Section D): ELEKTA LTD; linac house; fleming way; crawley, west sussex RH10 9RR; UK RH10 9RR
• Manufacturer (Section G): ELEKTA LTD; linac house; fleming way; crawley, west sussex RH10 9RR; UK RH10 9RR
• Manufacturer Contact: gpms ; linac house; fleming way; crawley, west sussex RH10 -9RR ; UK RH10 9RR
• MDR Report Key: 4597295
• MDR Text Key: 20127162
• Report Number: 9617016-2015-00003
• Device Sequence Number: 1
• Product Code: IYE
• Combination Product (y/n): N
• Reporter Country Code: UK
• PMA/PMN Number: K963624
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Manufacturer
• Source Type: Other,Health Professional,User Facility
• Reporter Occupation: Health Professional
• Remedial Action: Modification/Adjustment
• Type of Report: Initial,Followup
• Report Date: 06/11/2015

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Date FDA Received: 03/13/2015
• Is this an Adverse Event Report?: Yes
• Is this a Product Problem Report?: No
• Device Operator: Health Professional
• Device Model Number: 151255
• Is the Reporter a Health Professional?: Yes
• Date Manufacturer Received: 02/12/2015
• Was Device Evaluated by Manufacturer?: Yes
• Is the Device Single Use?: No
• Is This a Reprocessed and Reused Single-Use Device?: No
• Type of Device Usage: Reuse
• Patient Sequence Number: 1
• Patient Outcome(s): Other