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John Saunderson

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Can delegate authorisation to an operator in written procedures ... If procedures allow, can authorise exposure. Must follow employer's procedures . 4/3/09 ... – PowerPoint PPT presentation

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Title: John Saunderson


1
Radiation Protection for Assistant Practitioners
in MammographyLecture 4
  • John Saunderson
  • Radiation Protection Adviser
  • (TPRH ext. 6690)

2
IRMER Syllabus
  • Production of X-rays
  • Absorption and scatter
  • Radiation hazards and dosimetry
  • Special attention areas
  • Radiation Protection
  • Laws Guidelines
  • Equipment .

3
2. Management and Radiation Protection of Patient
4
2.1 Patient Selection
  • Justification of the individual exposure
  • Patient identification and consent
  • Use of appropriate radiological information
  • Alternative techniques
  • Clinical evaluation of outcome
  • Medico-legal issues .

5
Justification of the individual exposure
  • By law, all exposures must be justified
  • For breast screening
  • Women invited within NHSBSP invitation protocol
  • Women not invited, but fit NHSBSP protocol
  • For other, practitioner must decide (e.g.
    radiologist)
  • A written record must be made of who authorised
    each X-ray.

6
Patient identification and consent
  • (covered elsewhere)
  • By law, the Trust must have a patient ID
    procedure
  • ID should be positive (Yes, dear wont do!) .

7
General Points
  • Use of appropriate radiological information
  • (covered elsewhere)
  • Alternative techniques
  • Always use lowest dose technique, that will
    achieve the clinical result
  • Clinical evaluation of outcome
  • By law, all films must be reported
  • Medico-legal issues
  • e.g. X-rays for insurance purposes
  • Special procedures must be in place to ensure
    that exposures are justified .

8
2.2 Radiation Protection
  • General radiation protection
  • Use of radiation protection devices
  • patient
  • personal
  • Procedures for untoward incidents involving
    overexposure to ionising radiation .

9
  • Justification
  • Optimisation
  • Limitation

10
(No Transcript)
11
All doses should be kept
  • As
  • Low
  • As
  • Reasonably
  • Achievable
  • The ALARA Principle .

12
Basic Principles
  • Time
  • Distance
  • Shielding

13
Distance
  • Double distance 1/4 dose
  • Triple distance 1/9th dose.

14
Shielding
15
Shielding
16
Typical Mammo. Doses
  • Primary 5 mGy _at_ 1 m from tube per shot
  • Through breast to film 7 uGy
  • Max. scatter _at_ 1 m 7.6 uGy (at 163o)
  • _at_ 30 kV 0.3 mm Pb transmits 0.00006 (i.e. less
    than a millionth)

17
Organising radiation safety
  • Controlled Areas
  • Local Rules
  • Radiation Protection Supervisor
  • Radiation Protection Adviser
  • Radiographer
  • Assistant Practitioner .

18
Use of radiation protection devices
  • patient
  • personal

19
Untoward Incidents
  • Overexposure of patient
  • Overexposure of staff
  • ?.

20
Incidents
  • Any untoward occurrence which may result in
    excess radiation to staff or patients must be
    referred to the Radiation Protection Supervisor
    and the Radiation Protection Adviser, who will
    estimate the dose and liase with management, HSE,
    DoH, HMIP, etc. as appropriate
  • Suspect equipment must be withdrawn from service
    and labelled according .

21
Patient Doses Much Greater Than Intended
  • x 20 - extremities, skull, chest, etc.
  • x 10 - lumbar spine, abdomen, pelvis, mammography
    and other examinations not referred to elsewhere,
  • x 3 - fluoroscopy, digital radiography, C.T.

22
Investigation
  • establishing what happened
  • identifying the failure
  • deciding on remedial action to minimise the
    chance of a similar failure
  • estimating the doses involved
  • decide whether patient informed (usually yes).

23
3. Statutory Requirements and Advisory Aspects
24
3.1 Statutory Requirements and Non-Statutory
Recommendations
  • Regulations
  • Local rules and procedures
  • Individual responsibilities relating to medical
    exposures
  • Responsibility for radiation safety
  • Routine inspection and testing of equipment
  • Notification of faults and Health Department
    hazard warnings
  • Clinical Audit .

25
UK Regulations
  • Ionising Radiations Regulations 1999
  • IRR99
  • inspected by Health Safety Executive
  • Mostly relate to staff and public safety (not
    patients)
  • Covers equipment
  • Ionising Radiation (Medical Exposures)
    Regulations 2000
  • IRMER
  • Relate to patient safety .

26
IRR99
  • Justification, optimisation, limitation
  • Optimisation
  • ALARP,
  • controlled areas,
  • local rules,
  • RPS,
  • RPA,
  • risk assessments,
  • equipment QA.

27
IRMER
  • Justification, optimisation, constaints
  • Procedures and protocols
  • Roles and responsibilities
  • Audit and adequate training.

28
Employer's Procedures to ...
  • (a) identify patient correctly
  • (b) identify referrers, practitioners and
    operator
  • (c) for medico-legal exposures
  • (d) for making enquiries of females of
    childbearing age to establish whether the
    individual is or may be pregnant or
    breastfeeding
  • (e) ensure that QA programmes are followed
  • (f) for the assessment of patient dose
  • (g) diagnostic reference levels

29
Employer's Procedures to ...
(a) identify patient correctly (b) identify
referrers, practitioners and operator (c) for
medico-legal exposures (d) for making enquiries
of females of childbearing age to establish
whether the individual is or may be pregnant or
breastfeeding (e) ensure that QA programmes are
followed (f) for the assessment of patient
dose (g) diagnostic reference levels (h)
(biomedical research)
  • (i) (nuclear medicine)
  • (j) recording result and exposure factors
  • (k) minimise accidents.

30
Roles and Responsibilities
  • Employer
  • Referrer
  • Practitioner
  • Operator
  • Medical Physics Expert.

31
Referrer
  • Must provide sufficient info. for the
    practitioner to justify exposure
  • X-ray department must provide referral criteria.

32
Practitioner
  • Justifies X-ray - decides net benefit
  • Can delegate authorisation to an operator in
    written procedures
  • Usually a radiologist, but does not have to be -
    define in employers procedures
  • Must follow employers procedures .

33
Operator
  • Anyone who performs practical aspects, e.g.
  • radiographer
  • radiologist
  • assistant practitioner
  • medical physics
  • engineer
  • If procedures allow, can authorise exposure
  • Must follow employers procedures .

34
Training
  • Practitioners and operators must have adequate
    training
  • Schedule 2 lists theory, also do practical
  • Records must be available.

35
4. Diagnostic Radiology
36
4.1 General
  • Fundamentals of radiological anatomy
  • Fundamentals of radiological technique
  • Production of X-rays
  • Equipment selection and use
  • Factors effecting radiation dose
  • Dosimetry
  • Quality assurance and quality control .

37
4.3 Fundamentals of Image Acquisition, etc.
  • Image quality v. radiation dose
  • Conventional film processing
  • Additional image formats, acquisitions, storage
    and display .

38
f i n
39
Trash next
40
Attenuation, Scattering and Absorption
  • 0.34 mm Al at 28 kV Mo/Mo
  • For average breast
  • 0.2 of x-ray energy reaches film
  • 99.8 absorbed in breast
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