Medical device manufacturer, Elekta Limited, has issued a field safety notice concerning all MLCi and MLCi2 radiation heads.
According to Elekta, it is possible that the backup diaphragms drive mechanism can become loose after many years in clinical operation. This can cause a backlash between the positioning mechanism and the diaphragm. This backlash can be seen by the usual X-ray and field calibration checks when the field is moved from a small to a large field size. If there is a problem it will be that the backup diaphragm is not in the correct position behind the MLC leaf tips. If the affected customers do not do the recommended planned maintenance program, screws can become lost from the positioning mechanism.
As the problem can lead to clinical mistreatment if it is not repaired, customers are advised to conduct a weekly recommended physics check of the X-ray and light field size calibration to make sure the field is moved from a small to a large field size.
According to the local supplier, the affected devices have been distributed in Hong Kong. If you are in possession of the affected product, please contact your supplier for necessary actions.