Quality Control in Radiotherapy Flashcards
(23 cards)
Define quality management
The organisational processes that ensure quality is maintained.
State the 7 processes involved in quality management
- Design and implementation of mitigating factors
- Layered protections
- Risk management
- Incident reporting
- Machines management meeting
- Quality control
- Quality assurance
Define quality assurance
All the planned activities which provide confidence that a system will meet the requirements for quality.
State the 2 processes involved in quality assurance
- Regular review of linac trends
- Proactive maintenance
Define quality control
The operational techniques used to fulfill the requirements of quality.
State the 3 processes involved in quality control
- Definition of tolerance levels for performance characteristics
- Regular measurement of performance characteristics
- Reactive maintenance or recalibration once tolerances are breached
Describe the 5 stages in the lifecycle of a linac
1) Specification and contract: defining performance
2) Acceptance: measuring performance to confirm it meets contract specifications
3) Commissioning: fully characterising performance and setting QC baselines
4) Ongoing QA/maintenance: measuring the linac against QA specifications and doing proactive/reactive maintenance
5) Decommissioning/removal: ending QA programmes and archiving records
What is the purpose of acceptance testing?
For the supplier to demonstrate that the equipment meets the stated (pre-agreed) performance specification.
When does acceptance testing for a linac begin?
As soon as the equipment is installed.
What is the purpose of commissioning?
To prepare the equipment for clinical use.
What processes are involved in machine commissioning?
- Characterising the performance of the machine
- Measuring baseline standards
- Preparing procedures
- Training staff
- Configuring the machine
State the 6 key components of quality control specification
1) Deciding which characteristics need testing
2) Deciding which tests to perform
3) Defining tolerance levels for performance characteristics
4) Choosing what equipment to use
5) Organising how often to do each test
6) Producing competency records for doing the tests and reviewing the results
What is an action level?
The level above baseline at which investigation/recalibration is required. The machine is still okay to use at the action level.
What is a suspension level?
The level above baseline at which the equipment must be taken out of use and recalibrated. The machine shouldn’t be used clinically until this issue is solved.
How are QA tolerance levels chosen?
- The machine use/purpose (clinical context)
- The limitations of the measuring system (variability)
- The risk of recalibration
- Historical patient data
What are the 5 categories of QC test?
1) Safety
2) Treatment
3) Imaging
4) Mechanical
5) Connectivity
Give 5 examples of safety QC tests
- Interlocks
- Touch-guards
- Warning lights/alarms
- Electrical
- Mechanical
Give 4 examples of treatment QC tests
- Output
- Output linearity
- Energy
- Uniformity (flatness and symmetry)
Give 5 examples of imaging QC tests
- kV imaging quality
- Blade calibration
- CBCT dose
- CBCT HU
- Imaging isocentre calibration
Give 6 examples of mechanical QC tests
- Room lasers
- Light field
- Cross wire
- Accessories
- Scales and displays
- Robotic couch calibration
Give 6 examples of connectivity QC tests
- Data transfer and security
- Plan loading
- Record saving
- Image storage
- Gating connectivity
- TPS constancy
True or false: there is a specific way to measure each characteristic of clinical equipment during QC.
FALSE: each characteristic of the equipment can be measured in different ways. It isn’t always the best choice to follow the gold standard for every test.
State the 7 factors that determine the frequency of QC testing
1) Likelihood of fault
2) Consequence of a fault
3) Likelihood of fault detection by other means
4) Manufacturer’s recommendations
5) Published standards
6) Legal requirements
7) Resources (equipment/safety/staffing)
