BEUDAMED
    FDA Adverse Event Malfunction Summary report: N

    CORVUS

    MDR report key: 1059009 · Received June 9, 2008

    Report

    Report Number
    2434141-2008-00001
    Event Type
    Malfunction
    Date Received
    June 9, 2008
    Date of Event
    May 5, 2008
    Report Date
    June 3, 2008
    Manufacturer
    BEST NOMOS
    Product Code
    MUJ
    PMA / PMN Number
    K032209
    Product Problem
    Yes
    Report Source
    Manufacturer report
    Reporter Location
    GM
    Reporter Occupation
    PHYSICIAN

    Narratives

    Additional Manufacturer Narrative · 1

    IT SEEMS UNLIKELY THAT A SPURIOUS HOTSPOT CAUSED BY THIS PROBLEM WOULD MAKE A PLAN APPEAR MORE CLINICALLY DESIRABLE THAN THE REALISTIC PLAN AND THUS BE SELECTED FOR DELIVERY SINCE THE INVERSE PLANNING PROCESS SEEKS TO FIND THE BEST PLAN WHILE THE ERROR WOULD ADD DOSE IN SOME DIFFICULT TO PREDICT POSITION. A BULLETIN WAS SENT TO CUSTOMERS. THE ISSUE HAS BEEN CORRECTED IN CORVUS 08. UPDATED SOFTWARE WILL BE COMPLETED BY AUGUST 2008.

    Description of Event or Problem · 1

    A CORVUS USER DETECTED A DOSE CALCULATION PROBLEM WHERE A PARTICULAR ELEKTA MLC PLAN RESULTED IN A LIMITED REGION WITH INCORRECT DOSE. THE CALCULATION EXCEEDED THE CORRECT VALVE IN THIS LIMITED REGION FORMING A "HOTSPOT". A COMPARISON WAS MADE BEFORE AND AFTER CORRECTING THIS "HOTSPOT". IT IS WORTH NOTING THAT THE STATISTICS DID NOT CHANGE IN A SUBSTANTIAL MANNER UPON CORRECTED RECALCULATION SINCE THE MISCALCULATION WAS OF LIMITED EXTENT. THIS ISSUE WAS DISCOVERED IN CORCUS 6.3. THIS ISSUE COULD IMPACT CORCUS 5.0-6.3 CUSTOMERS USING THE ELEKTA MLC WHEN THE PT ORIENTATION IS PRONE, DECUBITUS RIGHT, DECUBITUS LEFT, UNK, OR FEET FIRST. THIS PT ORIENTATION IS SPECIFIED IN THE IMAGE REGISTRATION PANEL OF CORVUS. PLANS WITH BOTH SUPINE AND HEADFIRST PT ORIENTATION SPECIFIED ARE NOT AFFECTED BY THIS ISSUE. THE PROBLEM WAS DETERMINED TO BE ASSOCIATED WITH SELECTION OF A NON-SUPINE OR NON-HEADFIRST PT ORIENTATION. THE PROBLEM WAS LIMITED TO SOFTWARE WHICH RUNS ONLY FOR ELEKTA MLCS. A TRANSFORMATION PROBLEM IN THIS SOFTWARE COMPONENT WAS DETERMINED TO CAUSE AN INCORRECT CALCULATION OF LEAKAGE IN PARTS OF A BEAM THROUGH WHICH ONLY LEAKAGE FLUENCE PASSES. THIS ISSUE HAS LITTLE CLINICAL IMPACT. IN MANY CASES, IT MAY NOT BE POSSIBLE TO DETECT THE PROBLEM EVEN WHEN THE NECESSARY CONDITIONS FOR POTENTIAL IMPACT ARE MET. IF THE CONDITIONS ARE MET, THE CORRECTION DESCRIBED MAY FAIL TO INTERSECT THE PT GEOMETRY. THE REMAINING PORTION OF THE DOSE CALCULATION WOULD STILL BE CORRECT. SINCE THE CORRECTION COMPONENT MAY BE SMALL, THE DISCREPANCY MAY NOT BE DETECTED. THE DISCREPANCY WOULD TYPICALLY BE MOST SIGNIFICANT AND EASILY DETECTED WHEN USING FEW PORTS. WHEN MULTIPLE PORTS INTERSECT AT DIFFERENT ANGLES, THE EFFECT TENDS TO BECOME LESS SIGNIFICANT. THE CASE DETECTED WAS CHARACTERIZED BY AN INCORRECT AND DECREASED SSD IN THE LEAKAGE CORRECTION COMPONENT AND BY LEAKAGE GEOMETRY WHICH INTERSECTED THE PT VOLUME. IN THE CASE OBSERVED, THIS ISSUE RESULTED IN A LIMITED REGION OF SIGNIFICANTLY INCORRECT DOSE. WHILE THE MAGNITUDE OF THE DISCREPANCY IN THE LIMITED REGION WAS SIGNIFICANT, THE DISCREPANCY WAS NOT SUBSTANTIAL ENOUGH TO AFFECT THE STATISTICS REPORTED BY CORVUS.

    Devices

    Seq Brand Generic Product Code Manufacturer Model Lot UDI-DI
    1 CORVUS RADIATION THERAPY PLANNING SYSTEM MUJ BEST NOMOS 209359 NA

    Patients

    Seq Age Sex Outcome Treatment
    1