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IAEA Training Material on Radiation Protection in Radiotherapy

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... set of safety standards, such as the BSS, for day to day radiotherapy practice ... THE PAN AMERICAN HEALTH ORGANIZATION. and. THE WORLD HEALTH ORGANIZATION ... – PowerPoint PPT presentation

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Title: IAEA Training Material on Radiation Protection in Radiotherapy


1
IAEA Training Material on Radiation Protection in
Radiotherapy
Radiation Protection inRadiotherapy
Part 4 Principles of Radiation Protection Lecture
2 The BSS Framework
2
The IAEA
  • International Atomic Energy Agency
  • Objective to seek to accelerate and enlarge the
    contribution of atomic energy to peace, health
    and prosperity throughout the world.
  • Authorised to establish standards of safety for
    the protection of health and to provide for the
    application of these standards

3
IAEA assembly
4
The IAEA Basic Safety Standards
  • International Basic Safety Standards for
    Protection against Ionizing Radiation and for the
    Safety of Radiation Sources, IAEA Safety Series
    No 115, Vienna 1996 (IAEA, FAO, ILO, OECD/NEA,
    PAHO and WHO)

5
The Basic Safety Standards
  • Sponsored by many international institutions
  • A practical guide the BSS lays down basic
    principles and provides requirements for
    protection and safety
  • To be filled by more specific information through
    guidelines and codes of practice

6
Objectives of the lecture
  • To become familiar with the terminology and
    requirements of the BSS
  • To be able to apply the requirements of the BSS
    to the radiotherapy environment
  • To appreciate the importance of an
    internationally harmonized set of safety
    standards, such as the BSS, for day to day
    radiotherapy practice

7
Contents
  • 1. Background and structure of the BSS
  • 2. Some terminology
  • 3. BSS requirements
  • 4. The BSS Appendices and Schedules

8
1. Historical Background
  • First Basic Safety Standards 1962
  • Revised Basic Safety Standards 1967
  • Revised and Joint with FAO, ILO, OECD/NEA,
    WHO 1982
  • ICRP published revised recommendations 1991
  • Consultants, Senior experts meetings, ad hoc
    1991-1993
  • working groups, technical committees
  • 6th draft circulated to all member states Mar
    1994
  • 7th Draft approved by IAEA Board of Governors
    Sept 1994
  • Publication of Interim Version S.S.115I 1994
  • Formal approval by co-sponsoring organizations
    1994-1996
  • Publication of S.S.115 1996

9
  • Jointly sponsored by
  • THE FOOD AND AGRICULTURE ORGANIZATION OF THE
    UNITED NATIONS
  • THE INTERNATIONAL ATOMIC ENERGY AGENCY
  • THE INTERNATIONAL LABOUR ORGANIZATION
  • THE NUCLEAR ENERGY AGENCY OF THE OECD
  • THE PAN AMERICAN HEALTH ORGANIZATION
  • and
  • THE WORLD HEALTH ORGANIZATION

10
Hierarchy of IAEA documents
Safety Fundamentals
Safety Standards
Approved by IAEA Board of Governors
11
Hierarchy of IAEA documents
12
Objectives of the BSS
  • The objective is to establish basic requirements
    for protection against the risks associated with
    exposure to ionizing radiation and for the safety
    of radiation sources that may deliver such
    exposure.
  • The Standards have been developed from widely
    accepted radiation protection and safety
    principles, such as those published in the Annals
    of the ICRP and the IAEA Safety Series.

13
LAYOUT of the BSS
  • PREAMBLE Principles and Fundamental Objectives
  • PRINCIPLE REQUIREMENTS
  • General-responsibilities and organizational
  • Practices
  • Interventions
  • APPENDICES DETAILED REQUIREMENTS
  • Occupational exposure
  • Medical exposure
  • Public exposure
  • Potential exposure safety of sources
  • Emergency exposure situations
  • Chronic exposure situations
  • ANNEXES Numerical

14
The Scope of the BSS
  • The Standards comprise basic requirements to be
    fulfilled in all activities involving radiation
    exposure.
  • The Standards lay down basic principles and
    indicate the different aspects that should be
    covered by an effective radiation protection
    programme.
  • They are not intended to be applied as they stand
    in all countries and regions , but should be
    interpreted to take account of local situations,
    technical resources, the scale of installations
    and other factors.

15
Applicability of the BSS
  • The Standards apply to practices and
    interventions
  • (a) carried out in a State that adopts the BSS
  • (b) undertaken by States with assistance of FAO,
    IAEA, ILO, PAHO or WHO
  • (c) carried out by IAEA or with materials,
    services, equipment and non-published information
    made available by the IAEA
  • (d) where parties to bi/multi-lateral
    arrangements request application

16
EXCLUSION
  • Any exposure whose magnitude or likelihood is
    essentially unnamable to control, e.g.
  • 40K in the body,
  • cosmic radiation at earths surface
  • and unmodified concentrations of radionuclides in
    most raw materials.

17
EXEMPTION
  • Practice or source may be exempted if
  • effective dose lt 10mSv in a year
  • collective effective dose committed by one year
    of practice lt 1manSv
  • or
  • exemption is the optimum option (using model
    scenarios derived nuclide-specific levels)

18
GENERAL OBLIGATIONS
  • Unless excluded or exempted (numerical criteria
    nuclide specific values) the standards apply -
    including requirements for
  • notification
  • registration
  • licensing
  • Each application for authorization requires a
    safety assessment.
  • Each release of items from authorized premises
    requires clearance.

authorization
19
2. BSS Some Terminology
  • Definition of many terms is in
  • IAEA publication Safety Fundamentals, Safety
    Series 120, 1996 and
  • BSS glossary

20
Authorization registration or licensing
  • BSS 2.11. The Legal person responsible for any
    sealed source, unsealed source or radiation
    generator shall, unless the source is exempted,
    apply to the Regulatory Authority for an
    authorization which shall take the form of either
    a registration or a licence.

This applies to a radiotherapy department
21
Authorization registration or licensing
  • BSS 2.14. The legal person responsible for a
    source to be used for medical exposure shall
    include in the application for authorization
  • (a) the qualifications in radiation protection
    of the medical practitioners who are to be so
    designated by name in the registration or
    licence or
  • (b) a statement that only medical practitioners
    with the qualifications in radiation protection
    specified in the relevant regulations or to be
    specified in the registration or licence will be
    permitted to prescribe medical exposure by means
    of the authorized source.

This applies to radiotherapy
22
Authorized legal persons registrants and
licensees
  • BSS 2.15. Registrants and licensees shall bear
    the responsibility for setting up and
    implementing the technical and organizational
    measures that are needed for ensuring protection
    and safety for the sources for which they are
    authorized.
  • They may appoint other people to carry out
    actions and tasks related to these
    responsibilities, but they shall retain the
    responsibility for the actions and tasks
    themselves.

23
Quick question
Who is ultimately responsible for radiation
protection in your facility?
24
Practice
  • Any human activity that introduces or extends
    sources of exposure or exposure pathways.

Radiotherapy is a practice
25
Practices can alter exposure
Dose
Additional dose attributable to the practice, D
E
Post-practice extant dose
Pre-practiceextant dose
Time
Introduction, operation and decommissioning of a
beneficial practice
26
Intervention
  • Any action intended to reduce or avert exposure
    or the likelihood of exposure to sources which
    are not part of a controlled practice or which
    are out of control.

Without intervention radiotherapy would result in
large exposures not only for the patient but also
for staff, visitors and general public
27
Interventions
Averted dose by the intervention
Dose
Post-intervention dose
Pre-intervention dose
Time
Undertaking intervention
28
National Infrastructure
  • Enforcement of the Standards is the
    responsibility of national government. This
    requires a national infrastructure
  • Legislation Regulations
  • Regulatory Authority
  • Trained personnel

29
Regulatory Authority
  • ESTABLISHED BY GOVERNMENT
  • Given - Sufficient powers
  • - Resources
  • - Independence (effective)
  • To - Receive Notifications
  • - Carry out assessments
  • - Issue Authorizations/Licenses
  • - Inspect
  • - Enforce

30
3. The Principal Requirements of the BSS
  • Specifies who are the responsible
  • organizations and individuals, including the
    Regulatory Authority.
  • Defines the administrative requirements,
    including licensing and registration.
  • Uses the dose limitation system introduced in
    ICRP report 60.
  • The detailed requirements are given in a number
    of Appendices and Schedules.

31
Principal Requirements of the BSS
  • A) Allocation of responsibility
  • B) Administrative requirements
  • C) Radiation protection requirements
  • D) Management requirements
  • E) Technical requirements
  • F) Verification of Safety

32
A) Allocation of responsibilities
  • In radiotherapy
  • Emergency Situations
  • Occupational Exposure
  • Medical Exposure
  • Public Exposure
  • Safety of Sources

33
A) Allocation of responsibilities
  • In radiotherapy
  • Emergency Situations - part 13
  • Occupational Exposure - part 8
  • Medical Exposure - parts 9-12
  • Public Exposure - part 17
  • Safety of Sources - part 15

34
Responsibilities for Occupational Exposure
  • BSS Appendix I.1. Registrants and licensees and
    employers of workers who are engaged in
    activities involving normal exposures or
    potential exposure shall be responsible for
  • (a) the protection of workers from occupational
    exposure and
  • (b) compliance with any other relevant
    requirements of the Standards.

More details in part 8 of the course
35
Responsibilities for Medical Exposure
  • BSS Appendix II.1. Registrants and licensees
    shall ensure that
  • (a) no patient be administered a diagnostic or
    therapeutic medical exposure unless the exposure
    is prescribed by a medical practitioner
  • (d) for therapeutic uses of radiation, the
    calibration, dosimetry and quality assurance
    requirements of the Standards be conducted by or
    under the supervision of a qualified expert in
    radiotherapy physics

More details in parts 9 to 13 of the course
36
Responsibilities for Public Exposure (BSS III.2 )
  • III.1. Registrants and licensees shall apply the
    requirements of the Standards as specified by the
    Regulatory Authority to any public exposure
    delivered by a practice or source for which they
    are responsible, unless the exposure is excluded
    from the Standards or the practice or source
    delivering the exposure is exempted from the
    requirements of the Standards.

The BSS is applicable to radiotherapy - more
details in part 17 of the course
37
B) Administrative requirements
  • Notification
  • Authorization (Registration/Licensing)
  • as discussed before
  • included are requirements for authorized legal
    persons BSS 2.15. Registrants and licensees
    shall bear the responsibility for setting up and
    implementing the technical and organizational
    measures that are needed for ensuring protection
    and safety for the sources for which they are
    authorized. They may appoint other people to
    carry out actions and tasks related to these
    responsibilities, but they shall retain the
    responsibility for the actions and tasks
    themselves. Registrants and licensees shall
    specifically identify the individuals responsible
    for ensuring compliance with the Standards.

38
Notification
  • BSS 2.10. Any legal person intending to carry
    out any of the actions specified under the
    General Obligations for practices of the
    Standards (see paras 2.7 and 2.8) shall submit a
    notification to the Regulatory Authority of such
    an intention 6. Notification for consumer
    products is required only with respect to
    manufacturing, assembling, importing and
    distributing.

39
C) RADIATION PROTECTION REQUIREMENTS
  • Justification of Practices
  • positive net benefit
  • Dose Limitation
  • dose limits
  • Optimization of Protection and Safety
  • Constraints
  • of various types
  • guidance levels for medical exposure.

40
Radiation protection requirements
  • JUSTIFICATION OF PRACTICES
  • Practices should not be authorized unless the
    benefits are greater than the detriments, taking
    account of social, economic and other factors

41
Radiation protection requirements
  • DOSE LIMITATION
  • The normal exposure of individuals from
    authorized practices shall not exceed the dose
    limits specified in Schedule II of BSS

42
Dose limits - BSS schedule II
  • OCCUPATIONAL EXPOSURE
  • II-5. The occupational exposure of any worker
    shall be so controlled that the following limits
    be not exceeded
  • (a) an effective dose of 20 mSv per year
    averaged over five consecutive years
  • (b) an effective dose of 50 mSv in any single
    year
  • (c) an equivalent dose to the lens of the eye of
    150 mSv in a year and
  • (d) an equivalent dose to the extremities (hands
    and feet) or the skin 39 of 500 mSv in a year.

More details in part 8 of the course
43
Dose limits - BSS schedule II
  • PUBLIC EXPOSURE
  • II-8. The estimated average doses to the
    relevant critical groups of members of the public
    that are attributable to practices shall not
    exceed the following limits
  • (a) an effective dose of 1 mSv in a year
  • (b) in special circumstances, an effective dose
    of up to 5 mSv in a single year provided that the
    average dose over five consecutive years does not
    exceed 1 mSv per year
  • (c) an equivalent dose to the lens of the eye of
    15 mSv in a year and
  • (d) an equivalent dose to the skin of 50 mSv in
    a year.

More details in part 17 of the course
44
Radiation protection requirements
  • OPTIMIZATION OF PROTECTION AND SAFETY
  • Doses to individuals, the number of persons and
    the likelihood of incurring exposures shall be
    kept as low as reasonably achievable, economic
    and social factors taken into account

45
Radiation protection requirements
  • DOSE CONSTRAINTS
  • Optimization of protection and safety measures
    associated with a particular source within a
    practice shall be subject to dose constraints

Dose constraints are used prospectively e.g. at
the design stage of the facility
46
D) MANAGEMENT REQUIREMENTS
  • Safety Culture
  • Quality Assurance
  • Human Factors
  • Qualified Experts

47
Management requirements
  • SAFETY CULTURE
  • Purpose To encourage a questioning and learning
    attitude to protection and safety, whilst
    discouraging complacency. Policies and procedures
    should
  • identify protection and safety as the highest
    priority
  • Identify problems promptly
  • Identify responsibilities of individuals
  • define clear lines of authority (to the top)
  • effect lines of communication

48
Management requirements
  • QUALITY ASSURANCE
  • Establish QA programme to ensure
  • that safety and protection requirements are
    satisfied
  • the overall effectiveness of protection and
    safety is periodically reviewed
  • this requires significant commitment from
    management (logistical and financial resources)

49
Management requirements
  • HUMAN FACTORS
  • The contribution of human error to accidents
    should be minimized by
  • training of personnel
  • use of defined procedures
  • use of ergonomic design to minimize operating
    errors
  • use of safety systems

50
Management requirements
  • QUALIFIED EXPERTS
  • Identify need and make available, for example
  • Advice on radiation protection and safety
  • Servicing and maintenance
  • Calibration, clinical dosimetry...

51
E) TECHNICAL REQUIREMENTS
  • Security of Sources
  • prevent theft, damage and unauthorized use
  • keep under control at all times
  • receiver must posses valid authorization
  • carry out periodic inventory

52
TECHNICAL REQUIREMENTS
  • Defense in Depth
  • use of physical or procedural layers of
    protection to prevent accidents or mitigate
    consequences
  • built-in redundancy
  • Good Engineering Practice
  • equipment and facilities designed to
    (inter)national standards

53
F) Verification of Safety
  • Safety assessments
  • Monitoring and
  • verification
  • of compliance
  • Records

54
Safety assessments
  • BSS 2.37. Safety assessments related to
    protection and safety measures for sources within
    practices shall be made at different stages,
    including siting, design, manufacture,
    construction, assembly, commissioning, operation,
    maintenance and decommissioning, as appropriate,
    in order
  • (a) to identify the ways in which normal
    exposures and potential exposures could be
    incurred, account being taken of the effect of
    events external to the sources as well as events
    directly involving the sources and their
    associated equipment
  • (b) to determine the expected magnitudes of
    normal exposures and, to the extent reasonable
    and practicable, to estimate the probabilities
    and the magnitudes of potential exposures and
  • (c) to assess the quality and extent of the
    protection and safety provisions.

55
Monitoring and verification of compliance
  • BSS 2.38. Monitoring and measurements shall be
    conducted of the parameters necessary for
    verification of compliance with the requirements
    of the Standards.
  • BSS 2.39. For the purposes of monitoring and
    verification of compliance, suitable equipment
    shall be provided and verification procedures
    introduced. The equipment shall be properly
    maintained and tested and shall be calibrated at
    appropriate intervals with reference to standards
    traceable to national or international
    standards.

56
Records
  • BSS 2.40. Records shall be maintained of the
    results of monitoring and verification of
    compliance, including records of the tests and
    calibration carried out in accordance with the
    Standards.

57
4. Appendices and Schedules of the BSS
  • Detailed Requirements
  • Provide specific guidelines for practices
  • Followed by schedules which provide the
    numerical database for application of the
    standards

58
The Appendices to the BSS
  • I Occupational Exposure
  • II Medical Exposure
  • III Public Exposure
  • IV Potential Exposure Safety of Sources
  • V Emergency Exposure Situations
  • VI Chronic Exposure Situations

59
EXPOSURES
most important for radiotherapy are
  • Occupational exposure
  • Medical exposure
  • Public exposure
  • Appendix I (Part 8 of the course)
  • Appendix II (Parts 9 to 13)
  • Appendix III (Parts 16 and 17)

60
Exposures continued
  • Potential exposure - safety of sources
  • Emergency exposure
  • Chronic exposure
  • Appendix IV (covered in parts 14 and 15 of the
    course)
  • Appendix V (Part 13)
  • Appendix VI (not relevant for present course)

61
Schedules
  • I Exemptions
  • II Dose limits
  • III Guidance levels for medical exposure
  • IV Dose level for interventions
  • V Intervention and action levels for emergency
    exposure situations
  • VI Action levels for chronic exposure

62
Exemption criteria for practices
  • The additional individual dose attributable to
    the exempted practice should be of the order of
    10 uSv or less in a year
  • Either the collective dose committed by a year of
    practice should be lower than 1 man sievert,
    orexemption should be the optimum option.

63
mSv per year
Summary of limits and constraints
DOSE LIMIT
1
0.3
DOSE CONSTRAINT
OPTIMISATION
0.1
ADDED ANNUAL DOSEFROM PRACTICES
EXEMPTION
0.01
64
mSv in a year
Summary of action and intervention levels
1,000 300 100 30 10
3 1
INTERVENTION ALMOST ALWAYS REQUIRED
INTERVENTION MAY BE REQUIRED
INDIVIDUALS EXTANT ANNUAL DOSE
INTERVENTION USUALLY NOT REQUIRED
65
Any questions?
66
Question
Please discuss the differences between license
and registration as given in the BSS
67
License
  • BSS glossary An authorization granted by the
    Regulatory Authority on the basis of a safety
    assessment and accompanied by specific
    requirements and conditions to be complied with
    by the licensee.

68
Registration
  • BSS glossary A form of authorization for
    practices of low or moderate risks whereby the
    legal person responsible for the practice has, as
    appropriate, prepared and submitted a safety
    assessment of the facilities and equipment to the
    Regulatory Authority. The practice or use is
    authorized with conditions or limitations as
    appropriate. The requirements for safety
    assessment and the conditions or limitations
    applied to the practice should be less severe
    than those for licensing.

69
Registration and license...
  • Both are authorizations by the Regulatory
    Authority of a certain practice by a user.
    Radiotherapy requires a license!

70
Acknowledgments
  • Lee Collins, Westmead Hospital, Sydney
  • Pedro Ortiz, IAEA
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