Title: IAEA Training Material on Radiation Protection in Radiotherapy
1IAEA Training Material on Radiation Protection in
Radiotherapy
Radiation Protection inRadiotherapy
Part 4 Principles of Radiation Protection Lecture
2 The BSS Framework
2The 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
3IAEA assembly
4The 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)
5The 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
6Objectives 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
7Contents
- 1. Background and structure of the BSS
- 2. Some terminology
- 3. BSS requirements
- 4. The BSS Appendices and Schedules
81. 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
10Hierarchy of IAEA documents
Safety Fundamentals
Safety Standards
Approved by IAEA Board of Governors
11Hierarchy of IAEA documents
12Objectives 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.
13LAYOUT 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
14The 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.
15Applicability 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
16EXCLUSION
- 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.
17EXEMPTION
- 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) -
18GENERAL 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
192. BSS Some Terminology
- Definition of many terms is in
- IAEA publication Safety Fundamentals, Safety
Series 120, 1996 and - BSS glossary
20Authorization 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
21Authorization 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
22Authorized 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.
23Quick question
Who is ultimately responsible for radiation
protection in your facility?
24Practice
- Any human activity that introduces or extends
sources of exposure or exposure pathways.
Radiotherapy is a practice
25Practices 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
26Intervention
- 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
27Interventions
Averted dose by the intervention
Dose
Post-intervention dose
Pre-intervention dose
Time
Undertaking intervention
28National Infrastructure
- Enforcement of the Standards is the
responsibility of national government. This
requires a national infrastructure - Legislation Regulations
- Regulatory Authority
- Trained personnel
29Regulatory Authority
- ESTABLISHED BY GOVERNMENT
- Given - Sufficient powers
- - Resources
- - Independence (effective)
- To - Receive Notifications
- - Carry out assessments
- - Issue Authorizations/Licenses
- - Inspect
- - Enforce
303. 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.
31Principal 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
32A) Allocation of responsibilities
- In radiotherapy
- Emergency Situations
- Occupational Exposure
- Medical Exposure
- Public Exposure
- Safety of Sources
33A) 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
34Responsibilities 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
35Responsibilities 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
36Responsibilities 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
37B) 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.
38Notification
- 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.
39C) 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.
40Radiation 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
41Radiation protection requirements
- DOSE LIMITATION
- The normal exposure of individuals from
authorized practices shall not exceed the dose
limits specified in Schedule II of BSS
42Dose 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
43Dose 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
44Radiation 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
45Radiation 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
46D) MANAGEMENT REQUIREMENTS
- Safety Culture
- Quality Assurance
- Human Factors
- Qualified Experts
47Management 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
48Management 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)
49Management 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
50Management requirements
- QUALIFIED EXPERTS
- Identify need and make available, for example
- Advice on radiation protection and safety
- Servicing and maintenance
- Calibration, clinical dosimetry...
51E) 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
52TECHNICAL 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
53F) Verification of Safety
- Safety assessments
- Monitoring and
- verification
- of compliance
- Records
54Safety 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.
55Monitoring 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.
56Records
- 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.
574. 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
58The 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
59EXPOSURES
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)
60Exposures 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)
61Schedules
- 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
62Exemption 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.
63mSv per year
Summary of limits and constraints
DOSE LIMIT
1
0.3
DOSE CONSTRAINT
OPTIMISATION
0.1
ADDED ANNUAL DOSEFROM PRACTICES
EXEMPTION
0.01
64mSv 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
65Any questions?
66Question
Please discuss the differences between license
and registration as given in the BSS
67License
- 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.
68Registration
- 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.
69Registration and license...
- Both are authorizations by the Regulatory
Authority of a certain practice by a user.
Radiotherapy requires a license!
70Acknowledgments
- Lee Collins, Westmead Hospital, Sydney
- Pedro Ortiz, IAEA