Radiation Protection in Nuclear Medicine

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Part 12
IAEA Training Material on Radiation Protection
in Nuclear Medicine
Protection of the General Public
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Objective

• To become aware of the BSS requirements for the
  protection of the public and how these are
  applied to restrictions in the care of the
  nuclear medicine patients as well as the design
  and operation of a nuclear medicine facility

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Content

• Dose limits
• Design considerations
• The patient
• Special problems
• Transportation

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Exposure of the general public

• Spread of contamination outside the department
• Lost sources
• The nuclear medicine patient
• Disposal of radioactive waste
• Transportation of sources

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RESPONSIBILITIES

• BSS 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.

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Module 12.1. Dose limits
IAEA Training Material on Radiation Protection in
Nuclear Medicine
Part 12 Protection of the General Public
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(No Transcript)
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DOSE CONSTRAINTS

• If nationally not available, the local Radiation
  Protection
• Committee, should establish appropriate dose
  constraints, such as
• Co-workers to the patient, and other members of
  the general public 0.3 mSv/procedure

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Module 12.2. Design considerationsWorking
procedures
IAEA Training Material on Radiation Protection in
Nuclear Medicine
Part 12 Protection of the General Public
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RADIOACTIVE CONTAMINATION

• BSS III.7. Registrants and licensees shall
  ensure that
• (a) for sources for which they are responsible,
  measures that are optimized in
  accordance with the requirements of the
  Standards be taken as appropriate for restricting
  public exposure to contamination in
  areas accessible to the public and
• (b) specific containment provisions be
  established for the construction and
  operation of a source that could cause
  spread of contamination in areas accessible to
  the public.

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Reduce the risk of uncontrolled contamination

• Classification of areas
• Well trained staff
• Documented safe procedures in the handling of
  radiopharmaceuticals (receipt, preparation,
  administration, waste disposal)
• Workplace monitoring

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Layout of a nuclear medicine department
From high to low activity
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CLASSIFICATION OF AREAS

• Controlled area
• Supervised area

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CONTROL OF VISITORS

• BSS III.5. Registrants and licensees, in
  co-operation with employers when appropriate,
  shall
• (a) ensure that visitors be accompanied in any
  controlled area by a person
  knowledgeable about the protection and safety
  measures for that area
• (b) provide adequate information and instruction
  to visitors before they enter a
  controlled area so as to ensure
  appropriate protection of the visitors and of
  other individuals who could be affected
  by their actions and
• (c) ensure that adequate control over entry of
  visitors to a supervised area be
  maintained and that appropriate signs be
  posted in such areas.

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Patient areas

• Separation of radioactive patients and other
  patients waiting is an
• example of good practice, especially in a busy
  department.
• Separate toilet room for the exclusive use of
  injected patients should
• always be considered. This patient washroom
  should not be used by
• general public or hospital staff as it is
  likely that the floor, toilet seat and sink
  faucet handles will be contaminated
  frequently.

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STRUCTURAL SHIELDING

• The absorbed dose is determined by factors such
  as
• source strength
• length of exposure
• distance from the source
• transmission through the protective barrier.

Patient with I-131
General public
D mSv/h
0.3 mSv/procedure
Distance d
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STORAGE OF SOURCES

• locked to prevent unauthorized use
• and theft
• warning sign
• shielded to lt2 uSv/h at 1m
• (permanently occupied areas)
• alternatively lt20 uSv/h at 1 m
• (temporarily occupied areas)
• inventory record

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RADIOACTIVE WASTE

• BSS III.8. Registrants and licensees shall
• (a) ensure that the activity and volume of any
  radioactive waste that results from the sources
  for which they are responsible be kept to the
  minimum practicable, and that the waste be
  managed, i.e. collected, handled, treated,
  conditioned, transported, stored and disposed of,
  in accordance with the requirements of the
  Standards and any other applicable standard 26
  and
• (b) segregate, and treat separately if
  appropriate, different types of radioactive waste
  where warranted by differences in factors such as
  radionuclide content, half-life, concentration,
  volume and physical and chemical properties,
  taking into account the available options for
  waste disposal.

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Discharge of radioactive substances

• BSS III.9. Registrants and licensees shall
  ensure that radioactive substances from
  authorized practices and sources not be
  discharged to the environment unless
• (a) the discharge is within the discharge limits
  authorized by the Regulatory
  Authority
• (b) the discharges are controlled
• (c) the public exposures committed by the
  discharges are limited as specified in
  Schedule II and
• (d) the control of the discharges is optimized
  in accordance with the Principal
  Requirements of the Standards.

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Module 12.3. The patient
IAEA Training Material on Radiation Protection in
Nuclear Medicine
Part 12 Protection of the General Public
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The radioactive patient

• Uncontrolled radioactive source that causes
  external exposure and contamination of the
  general public?

YES! (after leaving the hospital)
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The Radioactive Patient
Contamination
External saliva
perspiration breath urine
0.5 0.1 0.06 0.03 mSv/h
1000 MBq I-131
0 0.5 1 2
m
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The radioactive patient
Exposure of general public
Release the patient without any restrictions

• Release the patient with restrictions

Keep the patient in the hospital
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Patient survey

• The dose rate at 1 m from the patient should be
  down to an acceptable level established by the
  RPC.
• Hospitalize
• gt1100 MBq I-131
• Release with restrictions
• Treatment of thyrotoxicosis
• Pain palliation (Sr-89, Sm-153)
• Lactating women (specified procedures)
• Release without restrictions
• Diagnostic procedures

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INSTRUCTIONS TO OUT-PATIENTS(Example to minimize
exposure of the general public)

• Use only a WC and flush 2-3 times. Keep the
  toilet and the floor clean.
• Wash Your hands frequently and take a shower
  every day.
• Avoid close contact to members of the family,
  children and pregnant women etc according to the
  time table attached
• Avoid solid waste

Off work 6d Avoid close contact
withchildren and pregnant women 20 d Public
travel 1h/day (1st week)
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Module 12.4. Special problems
IAEA Training Material on Radiation Protection in
Nuclear Medicine
Part 12 Protection of the General Public
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DEATH OF PATIENT
In the event of death of a patient who has
recently received a therapeutic dose of a
radionuclide care has to be taken to ensure that
personnel receive as low dose as possible at all
stages prior to the burial or cremation.
Activity (MBq)
(UK)
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DEATH OF PATIENT

• Precautions that should be given are depending on
  the residual activity
• and the expert advice provided by the RPO and may
  involve the following
• preparation for burial or cremation should be
  controlled by a
• competent person,
• relatives should be prevented from coming into
  close contact with the
• body,
• people should not be allowed to linger in the
  presence of the coffin,
• all personnel involved in handling the corpse
  should be instructed by
• the RPO and monitored if appropriate,
• all objects, clothes, documents etc that might
  have been in contact
• with the deceased must be tested for
  contamination,
• it may be expedient to wrap the cadaver in
  waterproof material
• immediately after death to prevent spread of
  contaminated body fluids,
• embalming of cadavers should, if possible, be
  avoided,
• autopsy of a highly radioactive cadavers should
  be restricted to the
• absolute minimum

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Module 12.5. Transportation
IAEA Training Material on Radiation Protection in
Nuclear Medicine
Part 12 Protection of the General Public
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TRANSPORT CONTAINER
Cartoon Liner Sealed can Liner Lead
container Source
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Transport Container
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Transport Index (TI)
1.0 m
TI max dose-rate _at_ 1.0m (?Sv/h)

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White-I Label

• lt 5.0 ?Sv/h _at_ surface
• lt 0.05 ?Sv/h _at_ 1.0 m
• TI 0

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Yellow-II Label

• lt 500 ?Sv/h, gt 5 ?Sv/h
• _at_ surface
• lt 10 ?Sv/h _at_ 1.0 m
• 0 lt TI lt 1.0

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Yellow-III Label

• gt 500 ?Sv/h,lt 2000?Sv/h
• _at_ surface
• gt 10?Sv/h, lt 100?Sv/h
• _at_ 1.0m
• 1.0 lt TI lt 10

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Vehicle Placards
3 placards on vehicle
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Consignors Responsibilities

• all labelling and placarding
• provision of transport documents
• provision of local rules and any other relevant
  information

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Internal transport
If the administration of radiopharmaceutical to
the patient takes place far from the dispensing
room, use a transport container with absorbent
pads. Make sure that a warning sign is on the
container together with patient name, activity
and date. Travel by the most direct route
avoiding more heavily occupied areas
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Questions?
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DISCUSSION
You get a phone-call from a colleague in
another hospital about 0.5 h away. He is in an
urgent need of Tc99m-MAA for a lung scan. Can
you help him?
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DISCUSSION
You get a phone call from a relative to a patient
whoyesterday got 4 GBq Sm-153. The patient died
at hometoday. What to do?
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DISCUSSION
A patient has received 300 MBq I-131 in a
treatmentof thyrotoxicosis. She is working in a
school preparingfood for the children. She was
told to stay off work for2 weeks. You get a
message that she actually wentback to work the
day after the treatment, which was10 days ago.
What to do?
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Where to Get More Information

• Other sessions
• Part 4. Security of sources, Design of facilities
• Part 5. Occupational protection
• Part 6. Medical exposure
• Part 8. Optimization of medical exposure.
  Therapeutic procedures
• Part 10. Radioactive waste
• Further readings
• IAEA Basic Safety Standards
• IAEA Model regulations on radiation safety in
  nuclear medicine (in preparation)
• WHO. Manual on Radiation Protection in Hospitals
  and General Practices. Volume 4 Nuclear Medicine
  (in preparation)