QA processes Flashcards
Rationale for QA in RT
- reduced random and systematic errors across all steps in process (improves dosimetric and geometric accuracy)
- increases probability that errors will be recognised and rectified sooner, reducing consequences for patient treatment
- allows reliable inter-comparison of results among different centres
Why is intercomparison important
Enhances accuracy or treatment
Highlights any deviations between machines, departments or techniques
Role of RT in QA
ASMIRT and MRPBA
Demonstrates a thorough knowledge of quality assurance (QA procedures)
➢ Knowledge and application of procedures used in QA, and follows
department policies and procedures
LINAC calibration protocols (national/international standard)
TRS 398 protocol
- AAPM –TG51 protocol
MDT in QA
- Radiation oncologists (ROs),
- Medical physicists,
- Radiation Therapists
- Nurses,
- Service engineers,
- Admin staff,
What is QA
Quality assurance (QA) - all those planned and systematic
actions necessary to provide adequate confidence that a
product or service will satisfy the given requirements for
quality.
➢ QA- addresses a range of procedures, activities, actions, and
groups of staff
what is QSM
Quality System Management (QSM)– is the management of a
QA program
Quality control
QC includes activities that impose specific quality on a process. It entails the evaluation of
actual operating performance characteristics of a device or a system, comparing it to desired goals
and acting on the difference.
(b) Is the regulatory process through which the actual quality performance is measured, compared
with existing standards, and the actions necessary to keep or regain conformance with the
standards.
- It is concerned with operational techniques and activities used:
➢ To check that quality requirements are met.
➢ To adjust and correct performance if the requirements are found not to have been met.
QA in RT definition and Examples of QA
all procedures that ensure consistency of
the medical prescription, and safe fulfilment of that radiotherapy-related
prescription.
Examples of prescriptions:
➢ Dose to the tumour (to the target volume).
➢ Minimal dose to normal tissue.
➢ Adequate patient monitoring aimed at determining the optimum
end result of the treatment.
➢ Minimal exposure of personnel
QA equipment programme
- Acceptance Testing and Commissioning
- Routine QC checks
- Additional QC checks
- Planned preventative maintenance (PM) program
Acceptance testing vs comissioning
Acceptance Testing – Acceptance of equipment is the process in which the
supplier demonstrates the baseline performance of the equipment to the
satisfaction of the customer.
- Commissioning - Commissioning is the process of preparing the equipment for
clinical service.
Regular QC
begins immediately after commissioning
Parameters to be tested and the tests to be performed.
✓ Specific equipment to be used for that.
✓ Geometry of the tests.
✓ Frequency of the tests.
✓ Staff group or individual performing the tests, as well as
the individual supervising and responsible for the
standards of the tests
✓ Expected results.
✓ Tolerance and action levels.
✓ Actions required when the tolerance levels are
exceeded.
frequency of QC checks
daily, monthly and annual
equipment of QC
Linac
✓ TPS
✓ RVs (R & V)
✓ RIS,
✓ PACs
✓ Hospital-based information systems
✓ QA equipment
ARPANSA role
Services include monitoring, Testing and Calibration, training and hire radiation
meters
Dosimetry Audits
The Australian Clinical Dosimetry Service (ACDS)
* A national independent dosimetry auditing program, providing quality assurance
for radiation oncology facilities and patients.
* ACDS Staff - MPs, 2 RTs,
Quality Audits definition
Quality audit is a systematic and independent
examination to determine whether or not quality activities and
results comply with planned arrangements and whether or
not the arrangements are implemented effectively and are
suitable to achieve the stated objectives.
Quality Audits rationale
Evaluate the need for improvement or corrective
action if those standards are not met
Quality audits characteristics and scope
Should be regular and form part of a quality feedback loop
to improve quality.
* Voluntary
* Regulatory
* Procedural or Practical
Scope:
1. Check Documentation
2. Check Measurements
3. Assess infrastructure
Quality Audits example
Example: International QA
Audit
1. IAEA/WHO TLD audit
▪ Small TL dosimeters (0.5 cm in diameter
and 2.5 cm long) are distributed by mail
to the participants for irradiation and
upon their return, they are read in the
IAEA’s Dosimetry Laboratory
▪ Criteria- TLD results 5%
The RPLD capsule is positioned
at your usual SAD
2 Gy to centre (the RPLD capsule) is at 10
cm depth.
ACDS
conducts audits
different levels of audits
Level 1 audit
The Level I mail-out audit is an independent measurement
of linac output under reference conditions.
* Optically Stimulated Luminescent Dosimeters (OSLDs) are
sent to a facility, irradiated, and returned to the ACDS for
analysis.
* All clinical photon and electron beams are included in the
audit.
level 2 audit
- once every 4 years
- a diagnostic test of TPS performance
- mail-out audit
- independent measurement of Linac output under reference conditions
level 3 audit
- audit determines absorbed dose to water delivered to selected points within an anthropomorphic phantom
- this is an end-to-end audit where the phantom undergoes all steps in the RT chain
when to do TPS QA
new TPS
upgrades
periodic QA checks
TPS QA - Checksum program
Monthly – e.g., performing checksums on beam data and executable files.
Rationale:
1. The program cannot be modified by the operators therefore it should be verified
that it has not been corrupted by any virus or wrong operations.
2. The beam data can be modified (e.g., new measurement more precise).
* If a virus corrupts programs or somebody makes a wrong operation on the system, a checksum
utility program pointing on the executables, beam data and other important files can identify the
problem
forms of peer review
- Physician-led case oriented: Radiation Oncologists-RTs, Physics (set-up differs)
- Tumour Board: Multiple physicians and members of the healthcare team from
diverse disciplines. - Chart Rounds
- Members of the treatment team review each case (e.g., doses,
fields, treatment plans, patient setup) - Morbidity and Mortality(M&M) rounds/case conferences: developed to provide a forum in which clinicians discuss adverse events in an
attempt to improve patient safety and care
Peer review - PRAT
The Royal Australian and New Zealand College of Radiologists (RANZCR)
Peer Review Audit Tool for Radiation Oncology (PRAT)
* Steps
1. Patient selection
2. Preliminary scoring of each case
3. Peer review meeting to discuss all cases and feed back to radiation oncologist
4. Subsequent re-audit of all cases where a change in management was discussed.
* QA committees
Cumulative errors
From:
Unmitigated failure modes
Plan complexity
Adhoc procedure variations
