Radiation Protection in Radiotherapy

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Radiation Protection inRadiotherapy
IAEA Training Material on Radiation Protection in
Radiotherapy

• Part 14
• Transport Safety

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Transport of sources

• A problem in external beam therapy only for
  dosimetric check sources and in the context of
  source replacement for a tele-therapy unit
• A day-to-day problem in brachytherapy

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Objective

• To understand the process of
• ordering
• storage
• accounting for
• and transport
• of radiation sources within the hospital and
  externally
• To appreciate the protection and safety issues
  associated with this process

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Contents

• 1 Notes on ordering of sources
• 2 Transport
• IAEA transport regulations
• external of the hospital
• internal
• 3 Storage and accounting
• Disposal discussed in part 15

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1. Ordering of sources

• Need authorization
• Require all relevant licenses
• Order from approved supplier
• More in part 18 of the course

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The BSS on ordering and transport

• General obligations
• 2.7. No practice shall be adopted, introduced,
  conducted, discontinued or ceased and no source
  within a practice shall, as applicable, be mined,
  milled, processed, designed, manufactured,
  constructed, assembled, acquired, imported,
  exported, distributed, sold, loaned, hired,
  received, sited, located, commissioned,
  possessed, used, operated, maintained, repaired,
  transferred, decommissioned, disassembled,
  transported, stored or disposed of, except in
  accordance with the appropriate requirements of
  the Standards, unless the exposure from such
  practice or source is excluded from the Standards
  or the practice or source is exempted from the
  requirements of the Standards, including the
  requirements of notification and authorization.

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Receiving of sources

• Consignments are often sent by default to the
  hospital store
• Care must be taken that
• either sources are directly sent to and received
  by the person who holds the appropriate license
  and has the appropriate expertise
• or that the hospital receiving officer is trained
  appropriately, records all details of the
  shipping and informs the responsible person in
  radiotherapy immediately
• Radioactive sources MUST not be allowed to be
  stored with other goods without being under
  immediate control of an appropriately trained
  person

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2. Transport of radioactive sources for
radiotherapy

• Between the radiotherapy center and outside
  facilities
• delivery of sources
• disposal of sources
• transport between hospitals
• Within the radiotherapy center

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BSS and transport

• General obligations
• 2.9. The transport of radioactive sources shall
  be subject to the requirements of the IAEA
  Regulations for the Safe Transport of Radioactive
  Material and any applicable international
  convention.

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Transport of Radioactive Material

• IAEA Safety Standards No. ST-1 Regulations for
  the Safe Transport of Radioactive Material, 1996
  Edition

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Objective of the IAEA Transport Regulations

• To protect persons, property and the environment
  from the effects of radiation during the
  transport of radioactive material. This
  protection is achieved by requiring
• containment of the radioactive contents
• control of external radiation levels
• prevention of criticality (not a concern for
  radiotherapy sources)
• prevention of damage caused by heat.

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Scope of the IAEA Transport Regulations

• The Regulations apply to the transport of
  radioactive material by all modes on land, water
  or in the air.
• The Regulations cover the design and manufacture
  of packaging, the preparation, consigning,
  loading, carriage, unloading and receipt of the
  packages.

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Types of Packages as defined by the IAEA
Transport Regulations

• Excepted package
• Industrial package Type 1, 2 and 3
• Type A package
• Type B(U) package
• Type B(M) package
• Type C package

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Type B container

• Used for transport of 60-Co sources for external
  beam therapy
• Used for 192-Ir sources for high dose rate
  brachytherapy

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Please note

• Usually the head of a 60-Co unit is NOT a
  suitable container for transport of the source!

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In practice

• The transport container and the treatment unit
  may be identical (as seen here for the Nucletron
  HDR brachytherapy afterloading unit)

Courtesy of Nucletron
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Gammamed mobile unit

• Must be labelled once source is present
• Easy to transport
• Must be accompanied by appropriately trained
  person

Courtesy of MDS Nordion
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The Transport Index

• The Transport Index is the maximum radiation
  level, in mSv/h, at a distance of 1 m from the
  external surface of the package, multiplied by
  100.
• The categories of packages, are determined by the
  Transport Index and the maximum radiation level
  at any point on the surface of the package.

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Categories of Packages
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White-I Label

• lt 5.0 ?Sv/h _at_ surface
• lt 0.05 ?Sv/h _at_ 1.0 m
• TI close to 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, lt 2000?Sv/h _at_ surface
• gt 10, lt 100?Sv/h _at_ 1.0m
• 1.0 lt TI lt 10

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Vehicle Placards

• Required every time activity is transported
• Need at least three
• Other documentation also required

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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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Package Labels

• Package type
• Isotope, activity, calibration date
• Transport index (surface dose)

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Potential problems in Brachytherapy

• Source order, delivery, calibration and
  acceptance
• Different units were used by the hospital (mCi)
  and the manufacturer (mg-Ra-equivalent) this led
  to an overdosage of 74 of one patient
• In three cases there was an underdosage due to
  the use of the sources without checking the
  source activity.

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Brachytherapy problems

• Source order, delivery, calibration and
  acceptance. Contributing factors
• Different units were used by the hospital and
  manufacturer
• Insufficient check of documents (order and
  delivery
• No source calibration by the users (source
  strength determination)

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Transport of sources between hospitals

• Brachytherapy sources prepared on a different
  site to where they are used
• often the case for highly specialized medical
  areas such as eye surgery
• Radioactive applicators stored at a different
  site to where they are used
• ophthalmic applicators

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Transport of sources between hospitals

• May be the case for entire HDR brachytherapy unit
  and control
• Infrastructure (cables, beds, theatre) in place
  at multiple locations

Courtesy of Nucletron
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Transport within a hospital

• Aim to minimize all transport needs by initial
  layout of the facility or choice of brachytherapy
  areas.

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Transport within a hospital

• Often required for brachytherapy
• Need mobile safe to suit the isotope in use

• Transport must be accompanied by an appropriately
  trained person at all times
• Labels required

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Transport containers

• Maximum dose rate at the surface should be
  lt100mSv/hr
• Should have large wheels to negotiate uneven
  surfaces
• Could double up as emergency storage container

Courtesy of Nucletron
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Transport within a hospital

• Some practical suggestions
• Transport routes must be chosen prior to
  transport and adhered to
• Avoid lifts
• Avoid public areas (not only to protect patients
  but also to minimize anxiety of patients and
  others)

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Transport of patients with radioactive implants

• Should be avoided for brachytherapy patients
• shielding is difficult
• the implant may move during transport
• Label and signs required

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Transport of patients with implants

• If possible, the activity should be removed prior
  to transport of the patient

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Disposal of sources

• Only to person licensed to do this
• Documentation required
• This is a potential for accidents
• Compare part 15 of the course

BIN
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3. Source storage

• See part 15 Safety of sources
• Before ordering sources it must be assured that
  they can be safely stored
• Information required for storage is similar to
  information required for transport

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Features of source storage

• Secure (lock and key)
• Labels
• Different compartments
• Shielding
• Easy access

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BSS on Security of sources

• 2.34. Sources shall be kept secure so as to
  prevent theft or damage and to prevent any
  unauthorized legal person from carrying out any
  of the actions specified in the General
  Obligations for practices of the Standards (see
  paras 2.7-2.9), by ensuring that
• ...
• (b) a source not be transferred unless the
  receiver possesses a valid authorization and
• (c) a periodic inventory of movable sources be
  conducted at appropriate intervals to confirm
  that they are in their assigned locations and are
  secure.

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In radiotherapy practice

• Source storage area should be close to areas
  where the sources are to be used (theatres,
  brachytherapy ward)
• Storage and transport containers are usually of
  different design - a storage container is NOT
  necessarily suitable for transport

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Emergency storage

• In brachytherapy an emergency storage container
  should be available in case a source must be
  removed form the patient.

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Emergency storage

• Next to temporary LDR implants in case sources
  must be removed for medical emergency
• Next to HDR applications in case the source gets
  stuck and the whole applicator has to be removed

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Summary

• Transport of sources is always a potential for
  exposure
• Source transport is mainly an issue in the
  context of brachytherapy
• Appropriate containers and labeling is required
• Transport issues can occur outside and inside of
  a radiotherapy facility

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Any questions?
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Question

• Please design a source inventory suitable for
  your institution.

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Some suggestions

• Should include
• Type of source
• Activity (and date of specification)
• Ordered by (authorization?)
• Received by
• Received when
• Storage where?

• Patient name and identification number (for
  brachytherapy patients)
• Used for?
• Can be disposed of when (if applicable)
• Disposed by
• Disposed when
• Disposed to

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Acknowledgment

• Lee Collins, Westmead Hospital, Sydney