Transcript Holmberg Cairo 2 The role of justification

Regional Workshop on Imaging Referral Guidelines
13-16 December 2015
Cairo, Egypt
The role of justification and radiation
protection of patients: IAEA perspective
Ola Holmberg, PhD
Head, Radiation Protection of Patients Unit (RPOP)
Division of Radiation, Transport and Waste Safety (NSRW)
Benefits of the use of radiation in medicine
Global increase in the use of radiation
7000
6000
1988
26 %
2008
5000
4000
122 %
3000
130 %
2000
1000
0
Number of diagnostic
procedures, million
Collective dose,
1000 man Sv
World population,
million
Global increase in the use of radiation
Diagnostic
radiology
Nuclear
medicine
3.6 billion procedures
annually* (incl. dental)
33.5 million procedures
annually*
Radiotherapy
5.1 million radiotherapy
treatment courses
annually*
* UNSCEAR 2008 Report
More can be done with radiation in medicine
• More equipment
• More complex equipment
• New technologies and techniques
Single slice CT Multi-Detector CT
Film  Computed & Digital Radiography
Hybrid imaging, PET-CT
Image-guided interventional procedures
Tomosynthesis
PACS, RIS,
IMRT, IGRT
etc…
Access vary around the world
Issues vary around the world
Tailored approaches needed
The increasing medical exposure
UNSCEAR 1993
Global annual per caput effective dose
The increasing medical exposure
UNSCEAR 2008
Global annual per caput effective dose
The increasing medical exposure
NCRP160 2009
U.S. annual per caput effective dose
“Do more good than harm”
“Primum non nocere”
Radiation saves lives
Radiation can cause harm
Short-term effects
(deterministic)
Long-term effects
(stochastic)
- Carcinogenesis
- Hereditary effects
- Effects in the
embryo/foetus
Patient dose and individual risk vary greatly
Lethal whole
body dose
Radiation
risk
0.01mSv
Annual dose
from natural
background
0.1mSv
1mSv
Tissue reactions
(skin, eye lens,..)
Increased risk of cancer
10
mSv
100
mSv
1 000
mSv
10 000
mSv
100 000
mSv
Radiography
Radiological
procedures
CT, NM, Image
guided interventional
procedures
Skin doses –
Image guided
interventional
procedures
Radiation
therapy,
mainly to the
target volume
Medical radiation can cause harm
• Over the last three decades, at least 3000 patients have been
reported to be affected by radiotherapy incidents and accidents.
This is likely grossly under-reported
• Radiation accidents involving medical uses have accounted for
more deaths and early acute health effects than any other type of
radiation accident, including accidents at nuclear facilities
A need for radiation protection in medicine
“Primum non nocere”
Radiation
risk
Achieve clinical
purpose
• ICRP principles of radiation protection
o Dose limits don’t apply to medical exposures
o Justification - net benefit for the patient
o Optimization - achieve clinical purpose with appropriate dose
management
Justification and optimization in medicine
Medical exposure is overwhelmingly the most significant
manmade source of exposure to the population from
ionizing radiation
Issues around the optimization (e.g. wide variation in doses
reported for the same type of CT-scan)
Issues around the justification (a substantial fraction of
radiological examinations may be inappropriate)
Justification of medical exposure
• Evidence that many individual medical procedures are lacking in
justification and optimization, giving rise to a very significant
unnecessary exposure of the world’s population
• A substantial fraction (20% to 40%) of individual radiological
examinations may be unnecessary
ICRP identifies three levels at which justification operates:
Level 1 deals with use of radiation in medicine in general
(In practice this is accepted as doing more good than harm, and its
justification is taken for granted)
Level 2 deals with specified procedures with a specified objective
(The aim at this level is to judge whether the procedure will improve
diagnosis or provide necessary information about those exposed)
Level 3 deals with the application of the procedure to an individual
(The particular application should be judged to do more good than harm for the
individual patient)
Justification of medical exposure
• What are the factors behind these unnecessary exposures?
• Lack of knowledge about the patient from referring physician (non-adequate
examination of patient, duplicate examinations)
• Lack of knowledge about the procedure or alternatives (benefits and/or
risks)
• Variations in local practice (not based on evidence but on “tradition”)
• Evidence not available to relevant healthcare providers
• Lack of certainty, confidence or experience (radiologist)
• Pressure and expectations from patient
• Referring physician is also the provider of the service (self-referral,
economic interest)
• Referring as a safeguard against possible malpractice liability (defensive
medicine)
• …
• End result: High and increasing “unnecessary radiation burden”
experienced by the global population – arising from different basic “drivers”
Addressing radiation risk
Q: Are there radiation risks to take into account?
A: We are uncertain. Uncertainty arises from numerous factors:
•
•
•
•
Uncertainty in radiation
risk estimation
Natural variation of
disease occurrence in
populations
Limited information on
exposed populations
Incomplete
understanding of the
origins and development
of cancer
Figure from: P.W. Horton: “Dose and risk: the hard facts”. In: PROCEEDINGS OF AN
INTERNATIONAL WORKSHOP ON JUSTIFICATION OF MEDICAL EXPOSURE IN
DIAGNOSTIC IMAGING”, IAEA IN COOPERATION WITH THE EC, BRUSSELS, 2–4
SEPTEMBER 2009
Addressing radiation risk
Q: So what can we do when we are uncertain of the risks?
A: We can apply the Precautionary Principle
• Act in a balanced way to reduce potential hazards before there
is strong proof of harm, taking into account the likely risks and
benefits of action and inaction
• In clinical imaging using ionizing radiation:
•
•
•
We are uncertain of the risks from imaging investigations using
ionizing radiation
We know that a significant percentage of imaging investigations
using ionizing radiation are unnecessary
As a scientific community, we owe it to the public to reduce
unnecessary exposures, and to look for the beneficial relatively
lower-dose alternatives in imaging, in a balanced way
IAEA statute
“To establish or adopt … standards of safety for
protection of health and minimization of danger to life …
and to provide for the application of these standards”
IAEA Safety Standards hierarchy
Safety Fundamentals
Safety
Requirements
Safety
Guides
Fundamental safety objectives
and principles for protecting
people and environment
moral obligation
Requirements that
must be met to ensure
protection of people and
environment
legal obligations, "shall"
Recommended
ways of meeting
the requirements,
“should”
All Safety Standards go through the IAEA Safety Standards Committees and Commission,
and receive formal Member State comments
International BSS
1996
IAEA Member States
(162)
Review
2005 - 2006
Revision
2007- 2011
IAEA and other
cosponsors:
FAO, ILO, NEA/OECD,
PAHO, UNEP, WHO, EC
IAEA approval
2011
Cosponsor approval
2012
Published
July 2014
International BSS
Essential
principles
(moral obligation)
Effects of
radiation
Recommendations
for protection
Essential
requirements
(legal obligation)
International BSS
• The International BSS
Represent an international consensus on
what must constitute a high level of
protection and safety
o Mandatory for Member States receiving
technical assistance from IAEA
o Used as a basis for many national
regulations
o Jointly sponsored by other international
organizations, allowing organizations to
provide consistent advice and assistance
to the various government agencies of
their Member States
o
New BSS - Justification of medical exposures
• Medical exposures shall be justified by weighing the diagnostic or
therapeutic benefits that they are expected to yield against the
radiation detriment that they might cause, with account taken of the
benefits and the risks of available alternative techniques that do not
involve medical exposure.
• Generic justification of a radiological procedure shall be carried out by
the health authority in conjunction with appropriate professional
bodies, and shall be reviewed from time to time, with account taken of
advances in knowledge and technological developments.
Who? – Respective roles and issues
Referring physicians
• Clinical context, medical history
• Defensive medicine
Radiological practitioner
• Knowledge about procedure –
benefits, risks, limitations
• Financial conflict of interest
“Request for consultation” versus
“order/instruction to perform”
Referral guidelines / criteria of appropriateness
..shall be carried out through consultation between the radiological
medical practitioner and the referring medical practitioner, ….
Justification for an individual patient
• What needs to be considered?
• Appropriateness of the request
• Urgency of the procedure
• Characteristics of the exposure
• Characteristics of the individual patient
• Relevant information from previous radiological procedures
 Particular attention to be taken for patients who are pregnant or
breast-feeding or are paediatric
 “Relevant national or international referral guidelines shall be
taken into account for the justification of the medical exposure of
an individual patient in a radiological procedure”.
Clinical Imaging Guidelines
Is it indicated?
Ionizing radiation
Imaging study
Conditions
Clinical Imaging
Guidelines
Guidelines that can be
used by a clinician
when deciding whether
or not a particular
imaging study is
justified, taking into
account risk and
benefit, for answering
the clinical question
about a patient who
exhibits a specific set of
conditions
Clinical Imaging Guidelines
• Clinical imaging guidelines (CIGs) are consensus
statements based on the best available evidence, to help
physicians to prioritize patients’ needs.
•CIGs for appropriate use of radiation in medical imaging
have been developed by professional bodies in several
countries.
• However, they are not available worldwide, particularly in
developing countries. Even in those countries where CIGs
exist, they are not integrated into daily medical practice.
MBUR6 EVIDENCE TABLE: Chronic back pain with no clinical or
serological indicators of infection or neoplasia
Royal College of
Radiologists (RCR)
MBUR6
Reference:
M04
Clinical/Diagnostic
Problem:
Chronic back pain with no clinical or serological
indicators of infection or neoplasia
Investigation:
MRI
Dose
None
Recommendation:
Indicated
Grade of
recommendation:
A-C
[C]
Comment:
MRI is the preferred investigation for the diagnosis of most
spinal diseases.
Median Delphi
Likert score for
consensus
Clin. problem
Mo
dalit
ies
Grading
Comments
6/7
6/7
7/7
6/7
Literature Search
Results: No.
found; No. used
Found – 138
Used – 13
Existing NICE,
SIGN & ACR
Appropriateness
Criteria:
Low Back Pain
http://www.acr.org/SecondaryMainMenuCategories/quality_s
afety/app_criteria/pdf/ExpertPanelonNeurologicImaging/Low
BackPainDoc7.aspx
Highest level of
evidence:
I
Date of Delphi
review:
2006
Composition of
Review Panel
(not for
publication):
Removed
Ref
Papers referenced / [Evidence level] / Key references/
Hyperlinks
American College of Radiology (ACR)
Western Australia
Clinical Imaging Guidelines
• CIG are expensive, time consuming and difficult to
•
•
•
•
•
produce and maintain
Several sets of high quality CIG exist and can be
adopted and adapted
Many differences exist between countries-expertise,
equipment, disease prevalence, IT infrastructure,
financial and other resources, access to care, level of
interest
Is adaptation/adoption of existing CIG preferable to
creation?
What resources are currently available?
What Are the major real and potential obstructions to
CIG deployment and use?
Clinical Imaging Guidelines
BSS on Review and records
• Licensees shall ensure that radiological reviews are
performed periodically at medical radiation facilities and that
records are maintained.
• Radiological reviews:
• Performed periodically by the radiological medical
practitioners at the facility
• Include an investigation and critical review of the
current practical application of the radiation
protection (justification and optimization)
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