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
Overview Background Daily output and QC checks Linac QC checks Problems and solutions Future solutions Conclusions
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
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
Database main menu
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.
Daily output and QC checks
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
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
Example Photon Beam Energy
Example X Ray Field Size
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
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
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
QC session sign off
QC Checklists
Electronic Notes System
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
Searching for previous work
Future solutions Constantly improving and updating Extension of the database to include Simulator QC Superficial Unit QC ICRs Sr checks
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
Acknowledgements Ted Stilwell Database creator Physicists and Engineers who have contributed feedback during the development