Important Safety Alerts

Medical device manufacturer, Brainlab, has issued a medical device safety alert concerning its iPlan RT , iPlan RT Dose (all versions) and BrainSCAN (discontinued).

The manufacturer is informing users of the following effect that has been identified for the Brainlab radiation treatment planning software iPlan RT, iPlan RT Dose and BrainSCAN (all versions) when using the Pencil Beam algorithm for dose calculation of small MLC-shaped fields:-

• The Pencil Beam algorithm refers to beam data which is acquired by performing dose measurements for Multileaf Collimator (MLC) fields at predefined field sizes and which are stored using the iPlan RT Physics Administration /BrainSCAN Beam Profile Editor.
• For each beam contained in a radiation treatment plan, dose calculation is performed based on these tabulated measurement values. If a beam's equivalent field size does not correspond to the measured field size, the measured values are interpolated accordingly. Due to an inaccurate implementation in the Brainlab radiation treatment planning software, this interpolation between two measured values is less accurate:-
  • a. the smaller the field; and
  • b. the further away the equivalent field size is from the measured value.

For certain treatment setups, this leads to the effect that an insufficient amount of Monitor Units (MU) is calculated and that consequently the delivered dose is lower than the planned dose.

For clarity, the delivered dose does not exceed the planned dose due to the described issue.

The manufacturer's analysis (based on data from more than 140 beam data sets for different MLCs) determined that the maximum dose deviation for a set of beam data for fields smaller than 10 mm is typically below 5% and only in rare cases between 5% and 10%. Larger deviations are theoretically possible, but not expected. Furthermore, the analysis showed for all MLCs that for fields larger than 10 mm the maximum dose deviation is typically below 3% and only in rare cases between 3% and 4%.

If dose deviations are not recognized by the user with the recommended treatment plan quality assurance, the irradiation of such a treatment plan might lead to ineffective radiation treatment.

The manufacturer will provide a software solution (iPlan RT) to prevent the described scenario from occurring.

According to the local supplier, the affected products are distributed in Hong Kong.

If you are in possession of the affected products, please contact your supplier for necessary actions.

Posted on 14 December 2016