Experiences of daily use of a database for linear accelerator quality control

Transcription

1 Experiences of daily use of a database for linear accelerator quality control McGrath N, Stilwell E, Budgell G, Beck J, Aziz T Christie Medical Physics & Engineering Manchester

2 Overview Background Daily output and QC checks Linac QC checks Problems and solutions Future solutions Conclusions

3 Background and Purpose A database has been developed (MS access) and brought into routine use for daily output checks and quality control (QC) check results The need for a database: Paper-light working Handwriting Consistency of data recorded

4 Background and Purpose Satellite working: 16 linear accelerators within the Christie network Database has been in use for: 18 months for linac QC 30 months for daily output checks

5 Database main menu

6 Daily output and QC checks Check-boxes are ticked to record that the daily QC tests have been done Ion chamber/daily check device results entered Doses are calculated by the database using stored calibration factors and the pressure from a networked barometer An instant green/amber/red tolerance is applied to the results.

7 Daily output and QC checks

8 Daily output and QC checks Easy verification of results by a physicist Saves time Avoids calculation errors Allows remote checking of results between sites Displays of monthly results are available

9 Linac QC A form is generated for each linac QC test Date, time and staff name are automatically entered Data boxes are set as compulsory or optional, as required Calculations are performed automatically Results compared with baseline data stored within the database

10 Example Photon Beam Energy

11 Example X Ray Field Size

12 Linac QC Tolerances are applied Can be linac specific if required Out of tolerance results are flagged as red External files can be linked to forms to record data Graphs of individual MLC leaf positions Shortcuts to work instructions Shortcuts to QC test schedule spreadsheets Opened from the database Tick off to record that the tests have been completed

13 Problems and solutions Gaining familiarity and coping with change! Replicating the conveniences of a paper logbook in an electronic form Final conclusions from a session Identifying what was carried out during a QC session Passing on information between sessions

14 Problems and solutions Results and final conclusions from a session QC session has to be concluded with a sign-off form Tick box indicating that linac is fit for clinical use Identifying what was carried out during a QC session Tick-boxes to show which tests have been performed Free text box for conclusions and comments Passing on information between sessions Electronic notes system Checked before the next QC session Signed and dated when issue has been addressed

15 QC session sign off

16 QC Checklists

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18 Electronic Notes System

19 Problems and solutions A series of search tools has been designed to allow quick and thorough review of data All occasions of a specified test filtered for linac and date range All the tests performed on a linac in a given date range Results can be directly accessed Reports exist to allow all the sign-off forms in a specified date range to be reviewed Used in monthly QC review meetings

20 Searching for previous work

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22 Future solutions Constantly improving and updating Extension of the database to include Simulator QC Superficial Unit QC ICRs Sr checks

23 Conclusions Improved consistency of data recording and results A number of QC tests have become quicker to carry out Easier to review results, plot trends and monitor QC Can be done remotely across multiple sites New tests and improvements can be implemented quickly Staff must adhere strictly to correct sign-off and information transfer procedures The time and effort required for it s development has been well worth it

24 Acknowledgements Ted Stilwell Database creator Physicists and Engineers who have contributed feedback during the development