Medical device manufacturer, Brainlab AG, has issued a medical device safety alert concerning its ExacTrac v. 6.x – Cone Beam Computed Tomography (CBCT) Import & Alignment Software [Software version: ExacTrac v. 6.x (v. 6.0.0, 6.0.1, 6.0.2, 6.0.3, 6.0.4, 6.0.5; and v. 6.1.0), in combination with Varian TrueBeam system only].

According to the manufacturer, if a user-defined actively re-reconstructed CBCT subvolume is imported into ExacTrac, ExacTrac cannot regard the position of this CBCT subvolume correctly. If the center of this subvolume differs from the center of the original CBCT volume, this leads to an erroneous calculation of patient shifts needed to move the patient to the planned treatment position. If the corresponding calculated shifts and rotations are applied with ExacTrac, the patient will be positioned incorrectly at the linear accelerator (linac). If not detected by the user, the radiation treatment dose at the linac may be delivered to an unintended target position. If the deviation exceeds clinically acceptable limits, this could result in ineffective treatment, serious patient injury, or even death of the patient.

The manufacturer advises users to take the following actions:-

• With immediate effect, do not use any actively re-reconstructed CBCT subvolumes from the Varian TrueBeam system with the Brainlab ExacTrac 6.x CBCT Import & Alignment Software module.
• Import exclusively original, not modified, CBCT volumes into ExacTrac to use for patient positioning.
• Continue to verify any ExacTrac CBCT-based correction using the ExacTrac X-ray verification and/or an external IGRT procedure as mandatory.

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 11 March 2015