Medical device manufacturer, RaySearch Laboratories AB, has issued a medical device safety alert concerning its RayStation 3.5, RayStation 4.0, RayStation 4.5, RayStation 4.7, RayStation 5, RayStation 6, RayStation 7, RayStation 8A [Build Number: 3.5.0.16, 3.5.1.6, 4.0.0.14, 4.0.1.4, 4.0.2.9, 4.0.3.4, 4.5.0.19, 4.5.1.14, 4.5.2.7, 4.7.0.15, 4.7.1.10, 4.7.2.5, 4.7.3.13, 4.7.4.4, 4.7.5.4, 5.0.0.37, 5.0.1.11, 5.0.2.35, 6.0.0.24, 6.1.0.26, 6.1.1.2, 6.2.0.7, 7.0.0.19, 8.0.0.61, 8.0.1.10.]
The manufacturer has become aware of an issue found with isocenter shifts when using dose tracking in the affected products. In these versions, isocenter shifts in dose tracking are incorrectly interpreted according to the DICOM patient coordinate system. When estimating fraction doses in the Dose Tracking module; it is possible to enter isocenter shifts as X, Y, Z in the Estimate Fraction Dose dialog. The coordinate system is not specified in the user interface, but the user manuals state that values in RayStation shall be entered according to the IEC patient coordinate system.
However, in the Estimate Fraction Dose dialog, coordinates are interpreted according to the DICOM patient coordinate system. This means that Y and Z values will be used incorrectly. The incorrect isocenter shifts will be visible in the dose views in the Dose Tracking module. The estimated fraction dose can be used as background dose for treatment adaptation. If the isocenter shifts are incorrect the background dose will also be incorrect, and the new adapted plan may not be as intended.
According to the manufacturer, the error only applies to the Dose Tracking module. The same function is available in the Plan Evaluation module when computing perturbed doses, but in the module X, Y, Z is correctly interpreted according to the IEC patient coordinate system. The issue has not caused any patient mistreatment or other incidents.
In the event that a clinical decision is based on an incorrect background dose, this could lead to the approval of an inappropriate dose plan, resulting in local over-dose in a risk organ from allowing too high of a dose in the treatment plan.
The issue will be resolved in the next version of RayStation. If customers wish to continue using versions of RayStation affected by this notice, all users must maintain awareness of the Field Safety Notice. Alternatively, the customers can choose to upgrade to the new version once it becomes available for clinical use.
According to the local supplier, the affected product is distributed in Hong Kong.
If you are in possession of the affected products, please contact your supplier for necessary actions.
Posted on 14 Nov 2018