Medical device manufacturer, RaySearch Laboratories AB, has issued a medical device safety alert concerning the following products:
The Field Safety Notice (FSN) concerns an incorrect information for the percent of a region of interest with a clinical goal that is outside the dose grid. For RayStation RayPlan 9B and 10A, 6D couch angles may be incorrect.
The two issues have not caused any patient mistreatment or other incidents. There is only a potential health hazard discovered by the manufacturer. However, the users must be aware of the information below to avoid inappropriate decisions during treatment planning and incorrect patient setup.
For "Percentage outside dose grid", the user can define clinical goals, i.e., evaluation criteria for specific regions of interest (ROIs). A clinical goal is reported in the graphical user interface (GUI) and in the treatment plan report as passed or failed. If an ROI is not completely covered by the dose grid, the pass/fail result reported for the clinical goal on the ROI may be misleading, as only the part of the ROI that is covered by the dose grid will be taken into account during dose computation. As a risk mitigation, the percentage of the ROI that is outside the dose grid (% outside grid) is displayed for each ROI with a clinical goal in the GUI and in the treatment plan report. In the GUI, this works as intended, but in the treatment plan report the percentage outside dose grid is incorrectly displayed. If up to 50% of the ROI is outside the dose grid, it will be reported as 0% outside grid. If more than 50% of the ROI is outside the dose grid, it is reported as 1% outside grid. The pass/fail result of clinical goals is the same in the GUI and in the treatment plan report. The error is that in the report the percentage outside the dose grid will never be shown as more than 1%.
For "Incorrect 6D couch angles in treatment plan report" (RayStation/RayPlan 9B and 10A only), 6D couch planning is only available with the ray6DCouchPlanning license. With this license couch pitch and couch roll can be set for treatment and setup beams. The values of couch pitch and couch roll for setup beams may be incorrect in the treatment plan report. All 6D couch angle values are correct in the exported DICOM files and they are correctly displayed in the GUI.
According to the manufacturer, users are instructed to do the following actions:
This issue will be resolved in the next version of RayStation and RayPlan scheduled for market release in November 2020 (subject to market clearance in some markets). If users wish to continue using versions of RayStation and RayPlan affected by this issue, they must maintain awareness of the FSN. Alternatively, users can choose to upgrade to the new version once it becomes available for clinical use.
According to the local supplier, the affected products are distributed in Hong Kong.
If you are in possession of the products, please contact your supplier for necessary actions.
Posted on 13 November 2020