RAYSTATION
Report
- Report Number
- 3007774465-2017-00004
- Event Type
- Malfunction
- Date Received
- December 21, 2017
- Date of Event
- November 7, 2017
- Report Date
- April 3, 2025
- Manufacturer
- RAYSEARCH LABORATORIES AB (PUBL)
- Product Code
- MUJ
- PMA / PMN Number
- K171536
- Product Problem
- Yes
- Report Source
- Manufacturer report
- Reporter Location
- CA
- Reporter Occupation
- OTHER
- Health Professional
- N
Narratives
THERE HAS BEEN NO ADVERSE EVENT. A SOFTWARE IMPLEMENTATION ERROR HAS BEEN IDENTIFIED DURING VALIDATION AT A CUSTOMER CLINIC. THIS IS A DESIGN DEFECT THAT HAS BEEN IDENTIFIED AND ISOLATED IN THE SOURCE CODE. IF THE ERROR IS TRIGGERED DURING BEAM COMMISSIONING, THIS WOULD LEAD TO AN INCORRECT BEAM MODEL. IN THIS CASE, THERE WOULD BE AN UNDERDOSAGE TO ALL ELECTRON PATIENTS, REGARDLESS OF THE NUMBER OF HISTORIES USED IN PLANNING. IF THE ERROR IS TRIGGERED DURING TREATMENT PLANNING, THE INCORRECT CALCULATED DOSE WOULD BE TOO LOW. IF THE PLAN WAS DELIVERED, THIS WOULD LEAD TO AN OVERDOSE. THE DOSE DEVIATION WILL DEPEND ON THE NUMBER OF HISTORIES USED AND THE APPLICATOR SIZE.
FOLLOW-UP OF REPORT RSL MDR: 3007774465-2017-00004 (B)(4) ELECTRON DOSE AT HIGH NO HISTORIES. THIS ISSUE WAS DETECTED BY A CLINIC. ISSUE: THIS NOTICE CONCERNS AN ISSUE FOUND WITH THE ELECTRON DOSE CALCULATION IN RAYSTATION 3.5, RAYSTATION 4.0, RAYSTATION 4.5, RAYSTATION 4.7, RAYSTATION 5, RAYSTATION 6, RAYPLAN 1 (RAYSTATION 4.9) AND RAYPLAN 2 (RAYSTATION 6). WHEN CALCULATING ELECTRON MONTE CARLO DOSE WITH A VERY LARGE NUMBER OF HISTORIES, THE DOSE CALCULATION MAY BE WRONG.TO THE BEST OF OUR KNOWLEDGE, THE ISSUE HAS NOT CAUSED ANY PATIENT MISTREATMENT OR OTHER INCIDENTS. HOWEVER, THE USER MUST BE AWARE OF THE FOLLOWING INFORMATION TO AVOID INCORRECT DOSE CALCULATIONS DURING BEAM MODELLING AND TREATMENT PLANNING. INTENDED AUDIENCE: THIS NOTICE IS DIRECTED TO ALL USERS OF RAYSTATION AND RAYPLAN WHO USE ELECTRON DOSE CALCULATION. DESCRIPTION: ELECTRON DOSE CALCULATION IN RAYSTATION USES A MONTE CARLO DOSE ENGINE, WHERE A LARGE NUMBER OF PARTICLES ARE SIMULATED. EACH SIMULATED PARTICLE IS CALLED A HISTORY, ADDING TO THE SIMULATED DOSE. THE NUMBER OF HISTORIES CAN BE ADJUSTED FOR EACH DOSE CALCULATION. GENERALLY, A HIGHER NUMBER OF HISTORIES LEADS TO A BETTER DOSE ACCURACY DUE TO LOWER STATISTICAL UNCERTAINTY BUT ADDS TO THE CALCULATION TIME. IN BEAM MODELING, USING A HIGHER NUMBER OF HISTORIES MAY ALSO BE DESIRED TO DETERMINE AN APPROPRIATE NORMALIZATION VALUE FOR COMMISSIONING THE TREATMENT MACHINE. WHEN STARTING THE DOSE CALCULATION, THE DATA VARIABLE REPRESENTING THE NUMBER OF HISTORIES IS ERRONEOUSLY CONVERTED TO A NUMBER FORMAT WHICH CANNOT HANDLE SUFFICIENTLY LARGE VALUES. THIS MEANS THAT WHEN A VERY LARGE NUMBER OF HISTORIES IS REQUESTED, THE MONTE CARLO DOSE ENGINE MAY USE A LOWER NUMBER OF HISTORIES THAN REQUESTED. AT THE END OF THE DOSE CALCULATION, THE RESULTING DOSE IS DIVIDED BY THE INTENDED NUMBER OF HISTORIES. THIS LEADS TO A CALCULATED DOSE THAT IS LOWER THAN THE ACTUAL DOSE. THE SHAPE OF THE DOSE DISTRIBUTION WILL BE CORRECT BUT THE ABSOLUTE DOSE LEVEL WILL BE WRONG. IN DETAIL, THE ERROR OCCURS WHEN THE TOTAL NUMBER OF HISTORIES (AREA × HISTORIES PER CM2) IS ABOVE THE MAXIMUM NUMBER A VARIABLE OF TYPE "UNSIGNED LONG" CAN REPRESENT, WHICH IS 4,294,967,295 (232-1). FOR EXAMPLE, FOR A 25 × 25 OPEN APPLICATOR (AREA OF 625 CM2), THE DOSE WILL BE INCORRECT IF THE NUMBER OF HISTORIES IS ABOVE 6,871,947 HISTORIES/CM2. FOR SMALLER OPENINGS, A LARGER NUMBER OF HISTORIES PER CM2 IS REQUIRED TO TRIGGER THE ERROR: (B)(6). THE TABLE SHOWS THE MAX NUMBER OF HISTORIES BELOW WHICH THE DOSE IS CORRECT. THE ERROR CAN ARISE DURING TREATMENT PLANNING IN RAYSTATION AND IN RAYPLAN, AS WELL AS DURING BEAM COMMISSIONING IN RAYPHYSICS AND IN RAYPLANPHYSICS. WHEN THE NUMBER OF HISTORIES DURING TREATMENT PLANNING IS ABOVE THE LIMIT, THE COMPUTED DOSE IS UNDERESTIMATED WHICH LEADS TO OVERDOSAGE. COMMISSIONING A MACHINE WITH A NORMALIZATION VALUE DETERMINED BY AN ERRONEOUS CALCULATION WOULD SCALE THE MONITOR UNITS SO THAT TOO FEW MONITOR UNITS ARE PRESCRIBED. THIS RESULTS IN AN UNDERDOSAGE TO ALL PATIENTS, REGARDLESS OF THE NUMBER OF HISTORIES USED IN TREATMENT PLANNING. IF THE LARGE NUMBER OF HISTORIES WHICH IS REQUIRED TO TRIGGER THE ERROR IS USED, THIS WOULD RESULT IN VERY LONG CALCULATION TIMES. THIS LARGE NUMBER OF HISTORIES IS ALSO WELL ABOVE THE REQUIRED NUMBER OF HISTORIES TO GET A CLINICALLY ACCEPTABLE DOSE ACCURACY. FOR AN INDIVIDUAL TREATMENT PLAN, THE ERROR COULD BE DETECTED BY COMMON CLINICAL KNOWLEDGE OF THE EXPECTED DOSE PER MONITOR UNIT RELATIONSHIP FOR ELECTRON BEAMS OR BY SECONDARY CALCULATIONS. FOR BEAM COMMISSIONING, THE ERROR COULD BE DETECTED BY VALIDATION OF THE BEAM MODEL. ACTIONS TO BE TAKEN BY THE USER. DO NOT USE A NUMBER OF HISTORIES ABOVE 6 MILLION FOR ELECTRON DOSE CALCULATION. INSPECT ALL COMMISSIONED ELECTRON BEAM MODELS FOR ANY APPLICATOR CALCULATED WITH GREATER THAN 6 MILLION HISTORIES. CONTACT CUSTOMER SUPPORT IF YOU HAVE ANY FURTHER QUESTIONS. PLEASE EDUCATE PLANNING STAFF AND ALL USERS ABOUT THIS WORKAROUND. INSPECT YOUR PRODUCT AND IDENTIFY ALL INSTALLED UNITS WITH THE ABOVE SOFTWARE VERSION NUMBER(S), THEN CONFIRM YOU HAVE READ AND UNDERSTOOD THIS NOTICE (CONTACT INFORMATION BELOW). SOLUTION: THIS ISSUE WILL BE RESOLVED IN THE NEXT VERSION OF RAYSTATION, SCHEDULED FOR MARKET RELEASE IN DECEMBER 2017 (SUBJECT TO MARKET CLEARANCE IN SOME MARKETS). IN THE MEANTIME, THIS FIELD SAFETY NOTICE IS DISTRIBUTED TO ALL CUSTOMERS. UNTIL A CORRECTED VERSION HAS BEEN INSTALLED, ALL AFFECTED USERS MUST MAINTAIN AWARENESS OF THE FIELD SAFETY NOTICE. TRANSMISSION OF THE FIELD SAFETY NOTICE: THE NOTICE NEEDS TO BE PASSED ON TO ALL THOSE WHO NEED TO BE AWARE WITHIN YOUR ORGANIZATION. PLEASE MAINTAIN AWARENESS OF THE NOTICE AS LONG AS ANY VERSION OF RAYSTATION AFFECTED BY THIS ISSUE IS IN USE TO ENSURE EFFECTIVENESS OF THE WORKAROUND.
FOLLOW-UP OF REPORT RSL MDR: 3007774465-2017-00004 (B)(4) ELECTRON DOSE AT HIGH NO HISTORIES. NO EVENT OCCURRED. THERE IS ONLY A POTENTIAL HEALTH HAZARD. ELECTRON DOSE CALCULATION IN RAYSTATION USES A MONTE CARLO DOSE ENGINE. A SOFTWARE ERROR IN THE ELECTRON DOSE CALCULATION WAS DISCOVERED BY A CUSTOMER IN THEIR VALIDATION PROCESS. IN THE MONTE CARLO DOSE ENGINE, A LARGE NUMBER OF PARTICLES ARE SIMULATED. EACH SIMULATED PARTICLE IS CALLED A HISTORY, ADDING TO THE SIMULATED DOSE. THE NUMBER OF HISTORIES CAN BE ADJUSTED FOR EACH DOSE CALCULATION. GENERALLY, A HIGHER NUMBER OF HISTORIES LEADS TO A BETTER DOSE ACCURACY DUE TO LOWER STATISTICAL UNCERTAINTY BUT ADDS TO THE CALCULATION TIME. WHEN CALCULATING ELECTRON MONTE CARLO DOSE WITH A VERY LARGE NUMBER OF HISTORIES, THE DOSE CALCULATION MAY BE WRONG. THE NUMBER OF HISTORIES WHICH IS REQUIRED TO TRIGGER THE ERROR RESULT IN VERY LONG COMPUTATION TIMES AND IS WELL ABOVE THE REQUIRED NUMBER OF HISTORIES REQUIRED TO GET A CLINICALLY ACCEPTABLE DOSE ACCURACY.
THIS ISSUE WAS DETECTED BY A US CLINIC. ISSUE: THIS NOTICE CONCERNS AN ISSUE FOUND WITH THE ELECTRON DOSE CALCULATION IN RAYSTATION 3.5, RAYSTATION 4.0, RAYSTATION 4.5, RAYSTATION 4.7, RAYSTATION 5, RAYSTATION 6, RAYPLAN 1 (RAYSTATION 4.9) AND RAYPLAN 2 (RAYSTATION 6). WHEN CALCULATING ELECTRON MONTE CARLO DOSE WITH A VERY LARGE NUMBER OF HISTORIES, THE DOSE CALCULATION MAY BE WRONG. TO THE BEST OF OUR KNOWLEDGE, THE ISSUE HAS NOT CAUSED ANY PATIENT MISTREATMENT OR OTHER INCIDENTS. HOWEVER, THE USER MUST BE AWARE OF THE FOLLOWING INFORMATION TO AVOID INCORRECT DOSE CALCULATIONS DURING BEAM MODELLING AND TREATMENT PLANNING. INTENDED AUDIENCE: THIS NOTICE IS DIRECTED TO ALL USERS OF RAYSTATION AND RAYPLAN WHO USE ELECTRON DOSE CALCULATION. DESCRIPTION : ELECTRON DOSE CALCULATION IN RAYSTATION USES A MONTE CARLO DOSE ENGINE, WHERE A LARGE NUMBER OF PARTICLES ARE SIMULATED. EACH SIMULATED PARTICLE IS CALLED A HISTORY, ADDING TO THE SIMULATED DOSE. THE NUMBER OF HISTORIES CAN BE ADJUSTED FOR EACH DOSE CALCULATION. GENERALLY, A HIGHER NUMBER OF HISTORIES LEADS TO A BETTER DOSE ACCURACY DUE TO LOWER STATISTICAL UNCERTAINTY, BUT ADDS TO THE CALCULATION TIME. IN BEAM MODELING, USING A HIGHER NUMBER OF HISTORIES MAY ALSO BE DESIRED TO DETERMINE AN APPROPRIATE NORMALIZATION VALUE FOR COMMISSIONING THE TREATMENT MACHINE. WHEN STARTING THE DOSE CALCULATION, THE DATA VARIABLE REPRESENTING THE NUMBER OF HISTORIES IS ERRONEOUSLY CONVERTED TO A NUMBER FORMAT WHICH CANNOT HANDLE SUFFICIENTLY LARGE VALUES. THIS MEANS THAT WHEN A VERY LARGE NUMBER OF HISTORIES IS REQUESTED, THE MONTE CARLO DOSE ENGINE MAY USE A LOWER NUMBER OF HISTORIES THAN REQUESTED. AT THE END OF THE DOSE CALCULATION, THE RESULTING DOSE IS DIVIDED BY THE INTENDED NUMBER OF HISTORIES. THIS LEADS TO A CALCULATED DOSE THAT IS LOWER THAN THE ACTUAL DOSE. THE SHAPE OF THE DOSE DISTRIBUTION WILL BE CORRECT BUT THE ABSOLUTE DOSE LEVEL WILL BE WRONG. IN DETAIL, THE ERROR OCCURS WHEN THE TOTAL NUMBER OF HISTORIES (AREA × HISTORIES PER CM2) IS ABOVE THE MAXIMUM NUMBER A VARIABLE OF TYPE "UNSIGNED LONG" CAN REPRESENT, WHICH IS 4,294,967,295 (232-1). FOR EXAMPLE, FOR A 25 × 25 OPEN APPLICATOR (AREA OF 625 CM2), THE DOSE WILL BE INCORRECT IF THE NUMBER OF HISTORIES IS ABOVE 6,871,947 HISTORIES/CM2. FOR SMALLER OPENINGS, A LARGER NUMBER OF HISTORIES PER CM2 IS REQUIRED TO TRIGGER THE ERROR: (B)(6). THE TABLE SHOWS THE MAX NUMBER OF HISTORIES BELOW WHICH THE DOSE IS CORRECT. THE ERROR CAN ARISE DURING TREATMENT PLANNING IN RAYSTATION AND IN RAYPLAN, AS WELL AS DURING BEAM COMMISSIONING IN RAYPHYSICS AND IN RAYPLANPHYSICS. WHEN THE NUMBER OF HISTORIES DURING TREATMENT PLANNING IS ABOVE THE LIMIT, THE COMPUTED DOSE IS UNDERESTIMATED WHICH LEADS TO OVERDOSAGE. COMMISSIONING A MACHINE WITH A NORMALIZATION VALUE DETERMINED BY AN ERRONEOUS CALCULATION WOULD SCALE THE MONITOR UNITS SO THAT TOO FEW MONITOR UNITS ARE PRESCRIBED. THIS RESULTS IN AN UNDERDOSAGE TO ALL PATIENTS, REGARDLESS OF THE NUMBER OF HISTORIES USED IN TREATMENT PLANNING. IF THE LARGE NUMBER OF HISTORIES WHICH IS REQUIRED TO TRIGGER THE ERROR IS USED, THIS WOULD RESULT IN VERY LONG CALCULATION TIMES. THIS LARGE NUMBER OF HISTORIES IS ALSO WELL ABOVE THE REQUIRED NUMBER OF HISTORIES TO GET A CLINICALLY ACCEPTABLE DOSE ACCURACY. FOR AN INDIVIDUAL TREATMENT PLAN, THE ERROR COULD BE DETECTED BY COMMON CLINICAL KNOWLEDGE OF THE EXPECTED DOSE PER MONITOR UNIT RELATIONSHIP FOR ELECTRON BEAMS OR BY SECONDARY CALCULATIONS. FOR BEAM COMMISSIONING, THE ERROR COULD BE DETECTED BY VALIDATION OF THE BEAM MODEL. ACTIONS TO BE TAKEN BY THE USER. DO NOT USE A NUMBER OF HISTORIES ABOVE 6 MILLION FOR ELECTRON DOSE CALCULATION. INSPECT ALL COMMISSIONED ELECTRON BEAM MODELS FOR ANY APPLICATOR CALCULATED WITH GREATER THAN 6 MILLION HISTORIES. CONTACT CUSTOMER SUPPORT IF YOU HAVE ANY FURTHER QUESTIONS. PLEASE EDUCATE PLANNING STAFF AND ALL USERS ABOUT THIS WORKAROUND. INSPECT YOUR PRODUCT AND IDENTIFY ALL INSTALLED UNITS WITH THE ABOVE SOFTWARE VERSION NUMBER(S), THEN CONFIRM YOU HAVE READ AND UNDERSTOOD THIS NOTICE (CONTACT INFORMATION BELOW). SOLUTION: THIS ISSUE WILL BE RESOLVED IN THE NEXT VERSION OF RAYSTATION, SCHEDULED FOR MARKET RELEASE IN DECEMBER 2017 (SUBJECT TO MARKET CLEARANCE IN SOME MARKETS). IN THE MEANTIME, THIS FIELD SAFETY NOTICE IS DISTRIBUTED TO ALL CUSTOMERS. UNTIL A CORRECTED VERSION HAS BEEN INSTALLED, ALL AFFECTED USERS MUST MAINTAIN AWARENESS OF THE FIELD SAFETY NOTICE. TRANSMISSION OF THE FIELD SAFETY NOTICE: THE NOTICE NEEDS TO BE PASSED ON TO ALL THOSE WHO NEED TO BE AWARE WITHIN YOUR ORGANIZATION. PLEASE MAINTAIN AWARENESS OF THE NOTICE AS LONG AS ANY VERSION OF RAYSTATION AFFECTED BY THIS ISSUE IS IN USE TO ENSURE EFFECTIVENESS OF THE WORKAROUND.
Devices
| Seq | Brand | Generic | Product Code | Manufacturer | Model | Lot | UDI-DI |
|---|---|---|---|---|---|---|---|
| 916847 | RAYSTATION | RADIATION THERAPY TREATMENT PLANNING SYSTEM | MUJ | RAYSEARCH LABORATORIES AB (PUBL) | RAYSTATION 6 |
Patients
| Seq | Age | Sex | Outcome | Treatment |
|---|---|---|---|---|
| 1 | NA | Unknown | Other |