Radiation Protection in Radiotherapy

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Radiation Protection inRadiotherapy
IAEA Training Material on Radiation Protection in
Radiotherapy

• Part 13
• Accidents and Emergencies
• Lecture 2 Emergencies

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Emergencies

• Some overlap with previous lecture
• Emergencies can occur, therefore it is essential
  to be prepared
• Important reference IAEA TECDOC 1162 Generic
  procedures for assessment and response during a
  radiological emergency, 2000

3
Clarification of terms

• BSS glossary
• Accident Any unintended event, including
  operating errors, equipment failures or other
  mishaps, the consequences or potential
  consequences of which are not negligible from the
  point of view of protection or safety.
• Emergency plan A set of procedures to be
  implemented in the event of an accident.

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BSS Appendix V EMERGENCY EXPOSURE SITUATION

• RESPONSIBILITIES
• V.1. It is presumed that the State will have
  determined in advance the allocation of
  responsibilities for the management of
  interventions in emergency exposure situations
  between the Regulatory Authority, national and
  local Intervening Organizations and registrants
  or licensees.
• The responsibility starts at the very top...

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Objectives

• To understand the need to plan for an emergency
  in radiotherapy
• To be able to respond adequately to an emergency
  in a radiotherapy department
• To identify the information which needs to be
  reported in case of an emergency

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Contents

• 1. Planning for an emergency
• 2. Emergency response and mitigation
• 3. Investigations and reporting

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1. Planning for an Emergency

• Consider what could happen
• Try to prevent it
• Prepare for the emergency situation
• internal (overdose of patients, malfunction of
  equipment)
• external (exposure of public and/or contamination
  of the environment)

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Need to differentiate type of emergency plan for

• Accidents involving the exposure of patients
  (previous lecture)
• Accidents involving the environment outside the
  hospital
• Radioactive sources used in radiotherapy are
  released into public
• Radiological emergencies of different origin may
  require radiotherapy staff to supply expertise
  and monitoring equipment

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Accidents involving the exposure of patients

• Considered in BSS in the context of medical
  exposure (appendix II 28,29)
• Discussed in detail in the previous lecture
• Panama accident an example

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Accidents involving sources from a radiotherapy
department causing exposure of general public

• Covered in BSS in appendix V Emergency Exposure
  Situations
• Includes also brachytherapy sources leaving the
  hospital
• Covered in more detail in part 15 of the course

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External accidents where equipment and/or
expertise from radiotherapy staff is required

• Staff in radiotherapy (in particular radiation
  safety officer and/or qualified expert in
  radiotherapy physics) have unique expertise which
  may also be useful in other radiological
  emergency situations
• Assessment of persons suspected of accidental
  exposure by radiation oncologists may be helpful
• Radiotherapy departments emergency plan may link
  to hospital or areas disaster plan

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BSS Appendix V EMERGENCY EXPOSURE SITUATION

• EMERGENCY PLANS
• V.2. Emergency plans shall be prepared which
  specify how the responsibilities for the
  management of interventions will be discharged on
  the site, off the site and across national
  boundaries, as appropriate, in separate but
  interconnecting plans.

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Emergency Planning and Preparedness in
radiotherapy

• assessment of the hazards
• acquisition of emergency equipment
• development of written procedures
• training

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BSS appendix V.4

• Emergency plans shall include, as appropriate
• (a) allocation of responsibilities for notifying
  the relevant authorities and for initiating
  intervention
• (b) identification of the various operating and
  other conditions of the source which could lead
  to the need for intervention
• (c) intervention levels, based on a
  consideration of the guidelines in Schedule V,
  for the relevant protective actions and the scope
  of their application, with account taken of the
  possible degrees of severity of accidents or
  emergencies that could occur

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BSS appendix V.4 (cont.d)

• Emergency plans shall include, as appropriate
  ...
• (d) procedures, including communication
  arrangements, for contacting any relevant
  Intervening Organization and for obtaining
  assistance from fire-fighting, medical, police
  and other relevant organizations
• (e) a description of the methodology and
  instrumentation for assessing the accident and
  its consequences on and off the site
• (f) a description of the public information
  arrangements in the event of an accident and
• (g) the criteria for terminating each protective
  action.

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Examples

• Can you report an example for an emergency in a
  radiotherapy department?

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Emergency plan - questions one should ask

• Is there a written emergency plan?
• Is the plan periodically reviewed and updated?
• Are staff aware of the plan and do they have
  training in the response required of them?
• e.g. Are there staff procedures for when a
  teletherapy or brachytherapy radiation source
  fails to return to the shielded position?
• Are there records of other or similar accidents?

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Please note

• These are also questions the regulatory authority
  may ask you...

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BSS appendix V.3.

• The appropriate responsible authorities shall
  ensure that
• (a) emergency plans be prepared and approved for
  any practice or source which could give rise to a
  need for emergency intervention
• (b) Intervening Organizations be involved in the
  preparation of emergency plans, as appropriate
• (c) the content, features and extent of
  emergency plans take into account the results of
  any accident analysis and any lessons learned
  from operating experience and from accidents that
  have occurred with sources of a similar type

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BSS appendix V.3. (cont.d)

• The appropriate responsible authorities shall
  ensure that
• (d) emergency plans be periodically reviewed and
  updated
• (e) provision be made for training personnel
  involved in implementing emergency plans and the
  plans be rehearsed at suitable intervals in
  conjunction with designated authorities and
• (f) prior information be provided to members of
  the public who could reasonably be expected to be
  affected by an accident

Test the emergency plan!
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Training

• personnel should be trained to deal with
  identified situations
• drills and exercises should be conducted
• include feedback from exercises to improve
  training

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Emergency drills

• All relevant actions must be trained and
  regularly performed to be proficient at the time
  of an accident
• Regular drills are important, e.g.
• Manual removal of a source in brachytherapy
• Removal of a patient from a treatment couch after
  power failure

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Emergency drills and exercises

• May be planned
• May be not announced to test response in a real
  situation
• The latter may also be used to audit the
  emergency preparedness

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Emergency drills and exercises

• Documentation important
• Planning needs to be done carefully to avoid
  interference with patient treatment
• De-briefing of staff essential
• Findings should be public and considered for
  revision of emergency plan and training programs

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Emergency Equipment

• Integral part of the emergency plan
• Manual, procedures, documentation
• Radiation monitor
• Other items as required by the specific
  application
• Only of use if staff is trained to use it

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2. Emergency response and mitigation

• Emergency procedures spell out mitigation
  measures
• Procedures shall be succinct, unambiguous and
  posted where ever need is anticipated
• Responsibilities of individuals shall be
  identified

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Emergency response - initial actions

• Rectify the situation (e.g. stop irradiation,
  manually retract a source)
• Make sure patients are brought into safety
• Isolate the area
• Notify supervisor and/or radiation safety officer

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Quick question for illustration

• Consider a patient with a radioactive implant
  (e.g. 198-Au seeds) has a cardiac arrest - what
  is to be done?

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Some additional suggestions for the answer

• The patients welfare is the highest priority
  therefore resuscitation should be commenced
  immediately. Also cardiac arrest team and
  radiation safety officer should be informed and
  called immediately. The dose for anyone in close
  contact with a patient having an implant does
  typically not exceed 1mSv in an hour. The
  radiation safety officer must try to estimate the
  dose received by all persons involved.

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Other important points

• Any incident should be reported in writing
• An accident may need formal investigation
• Doses can be reconstructed and should be reported
  for all persons involved - this includes the
  patient!
• Reporting of an incident outside the hospital may
  be required by law!!!

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Quick question

• What is a radiation accident in radiotherapy for
  you?

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3. Investigation

• BSS Appendix II INVESTIGATION OF ACCIDENTAL
  MEDICAL EXPOSURES
• II.29. Registrants and licensees shall promptly
  investigate any of the following incidents
• (a) any therapeutic treatment delivered to
  either the wrong patient or the wrong tissue, or
  using the wrong pharmaceutical, or with a dose or
  dose fractionation differing substantially from
  the values prescribed by the medical practitioner
  or which may lead to undue acute secondary
  effects
• ...
• (c) any equipment failure, accident, error,
  mishap or other unusual occurrence with the
  potential for causing a patient exposure
  significantly different from that intended.

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Investigation

• Things for the licensee or registrant to do
  following BSS II 29
• Calculate or estimate the dose(s) received and
  their distribution within the patient
• Indicate corrective measures to prevent a
  recurrence of the incident
• Implement all corrective measures under their
  control
• Submit a written report to the Regulatory
  Authority as soon as possible after the
  investigation or as otherwise specified by the
  Regulatory Authority

How bad was it? What to do to put it right?
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Flow chart may be useful
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Investigation level

• BSS IV.18. Registrants and licensees shall
  conduct formal investigations as specified by the
  Regulatory Authority if
• (a) a quantity or operating parameter related to
  protection or safety exceeds an investigation
  level or is outside the stipulated range of
  operating conditions or
• (b) any equipment failure, accident, error,
  mishap or other unusual event or circumstance
  occurs which has the potential for causing a
  quantity to exceed any relevant limit or
  operating restriction.

Did it exceed the level (or might it have)?
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In radiotherapy practice

• Investigation levels mainly applicable to
  occupational exposure
• For medical exposure the definition of an
  incident/accident may be relevant
• e.g. if the total dose delivered is different
  from the prescribed by more than 10
• This could be too much but also not enough dose...

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Investigation

• Should be done as soon as possible after the
  incident
• Often useful a written statement of all
  witnesses before they talk to each other
• Incident review meeting including a
  representative of senior management
• Assessment of impact on staff and patient
• Information for affected patient(s)

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Investigation

• Expertise of other professionals (e.g.
  Occupational Health and Safety, Environment) can
  be useful
• Could be most effectively lead by an external
  expert
• Feedback important
• A written report should be provided

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Report to

• Hospital management
• Regulatory authority
• IAEA?
• Professional organizations?

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Help may be available

• Radiological accident assistance
• e.g. outside assistance after radiological
  incident in Panama

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The Response

• The ION (Hospital) contacted the office of
  WHO/PAHO who made a calculation with the provided
  treatment time and other parameters. PAHO also
  confirmed
• The ION requested an expert group from MD
  Anderson who performed the mission in April 2000
  and confirmed the differences in doses
• 14 May the ION informed the Ministry of Health
  and the DSR
• 22 May a formal request for assistance was
  requested from the Agency
• The mission started in May 27

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The terms of reference for IAEA expert team

• Ensure that radiation sources are in safe
  conditions
• Evaluate the doses to patients
• Perform a medical evaluation, prognosis and
  advice on treatment
• Evaluate issues on which the IAEA can coordinate
  assistance to minimize the consequences

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Databases

• Several data bases exist which allow the
  comprehensive evaluation of causes for accidents
  and emergencies in radiotherapy
• Examples IAEA RADEV
• These databases rely on accurate and prompt
  reporting

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Disseminate information within professional
community

• A chance to learn
• Make sure legal investigations are not interfered
  with
• Make sure no one can be identified

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Actions after an accident in radiotherapy

• Investigation
• Report
• Actions to prevent a recurrence of the accident
• not necessarily closure of the radiotherapy
  facility ...

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A final commentRadiotherapy can cure cancer

• An uncontrolled cancer can look just like a
  deterministic radiation effect - and can kill a
  patient in the same way

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Radiotherapy should go on...

• A treatment unit may treat hundreds of patients
  per year - even if only a fraction of them is
  cured this constitutes a significant contribution
  to public health
• Clearly, an accident
• SHOULD be prevented
• MUST be investigated and
• a recurrence MUST be made impossible,
• however, if at all possible

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Summary

• It is essential to be prepared for a radiological
  emergency in radiotherapy
• Important elements of this are training, written
  procedures, emergency equipment and regular
  drills
• All accidents and emergencies MUST be reported
  and investigated
• A report may be required also to regulatory bodies

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Any questions?
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Question
Defence in depth may be an important part of
the preparedness for an emergency. Please discuss
the defence in depth approach in the context of
avoiding a lost source in brachytherapy.
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The answer should include at least the following
points 1. Procedures for receiving of sources 2.
Storage and identification of sources 3.
Accounting for sources 4. Monitoring of the
treatment room - including the exit 5. Monitoring
of the patient prior to discharge 6. Independent
check 7. Source inventory 8. Regular checks of
all sources in stock - identification, leak test