Radiation Safety Induction for Radiology Registrars

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Do not adjust your set
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www.hullrad.org.uk
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Radiation Safety Induction for Radiology
Registrars

• John Saunderson
• Radiation Protection Adviser
• CHH ext 76-1329

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Ionising / Non-ionising

• Ionising radiations
• x-rays
• gamma rays (?-rays)
• beta particles (?)
• electron beams

• Not ionising radiations
• lasers
• ultraviolet (UV)
• infrared (IR)
• ultrasound
• MRI

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Wilhelm Roentgen

• Discovered X-rays on 8th November 1895 .

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Colles fracture 1896 .
Frau Roentgens hand, 1895
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Mihran Kassabian (1870-1910)
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Dose Reduction Precautions

• X-ray tubes shielded
• Collimation
• Aluminium filters
• Weekly exposure limits introduced

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Radiation Effects

• Acute radiation syndrome
• Including vomiting, diarrhea, reduction in the
  number of blood cells, bleeding, epilation (hair
  loss), temporary sterility in males, and lens
  opacity (clouding )

• Late 1940s Dr Takuso Yamawaki noted an increase
  in leukaemia
• 20 of radiation cancers were leukaemia (normal
  incidence 4)
• Incidence peaked at 6-8 years
• Solid cancers excess seen from 10 years onwards.

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• Early X-ray pioneers
• Acute effects
• Precautions introduced
• Atomic bomb survivors
• Acute effects similar in nature to pioneers
• Some increased cancer risk
• But what about radiology today?

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Cancer Risk

• 1 in 20,000 risk of fatal cancer per millisievert
• Chest x-ray 0.02mSv ? 1 in a million risk
• Abdomen x-ray 1mSv ? 1 in 20,000
• Barium meal 3mSv ? 1 in 7,000
• CT abdomen 10mSv ? 1 in 2,000
• (Typical interventional radiologist dose lt 3
  mSv/y)
• Small risk compared to natural cancer risk
• Why worry?

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700 CANCER CASES CAUSED BY X-RAYS
30 January 2004

• X-RAYS used in everyday detection of diseases and
  broken bones are responsible for about 700 cases
  of cancer a year, according to the most detailed
  study to date.
•  
• The research showed that 0.6 per cent of the
  124,000 patients found to have cancer each year
  can attribute the disease to X-ray exposure.
  Diagnostic X-rays, which are used in conventional
  radiography and imaging techniques such as CT
  scans, are the largest man-made source of
  radiation exposure to the general population.
• Although such X-rays provide great benefits, it
  is generally accepted that their use is
  associated with very small increases in cancer
  risk.
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Average X-ray examination dose 0.5mSv ? 1 in
40,000 risk UK Radiology 41.5 million X-rays
per year
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Basic Principals of Radiation Protection

• Justification
• Benefit gt risk
• Optimisation
• Doses as low as reasonably achievable
• Limitation
• Absolute legal limits for staff and public
• Reference levels as guidance for patients.

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Regulations

• Ionising Radiations Regulations 1999 (IRR99)
• Local rules, radiation protection supervisors
• Ionising Radiation (Medical Exposures)
  Regulations 2000 (IRMER2000)
• Referrers, practitioners, operators
• Justification optimisation
• Medicines (Administration of Radioactive
  Substances) Regs 1978 (ARSAC)
• Nuclear medicine

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Organising radiation safety

• Controlled Areas
• Local Rules
• Radiation Protection Supervisor
• Radiation Protection Adviser
• Radiographer.

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IRMERIonising Radiation (Medical Exposures)
Regulations 2000

• Referrers
• allowed to request medical exposure
• Trust decides who can e.g. GP, consultant, etc.
• Practitioners
• Justifies X-ray - decides there is net benefit
• Trust decides who can e.g. radiologist
• Operator
• Performs practical aspects
• Trust decides who can e.g. radiographer,
  technician .

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Medicines (Administration of Radioactive
Substances) Regs 1978 (MARS / ARSAC)

• No person shall administer to a human being
  (otherwise than to himself) any radioactive
  medicinal product unless he is doctor or dentist
  holding a certificate issued by the Health
  Minister for the purposes of section 60 of the
  Act in respect of radioactive medicinal products
  (hereinafter referred to as a certificate) or a
  person acting in accordance with the directions
  of such a doctor or dentist. .

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Radiation in hospitals

• Radioactive substances
• nuclear medicine
• pathology
• radiotherapy
• X-ray sources
• Radiology
• Radiotherapy
• Pathology .

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Leakage
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Basic Principles

• Time
• Distance
• Shielding

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Distance

• Double distance 1/4 dose
• Triple distance 1/9th dose.

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Shielding
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Shielding
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Typical Transmission through Shielding (90 kV)

• 0.25 mm lead rubber apron ? 8.5
• 0.35 mm lead rubber apron ? 5
• 2 x 0.25 mm apron ? 2.5
• 2 x 0.35 mm apron ? 1.0
• Double brick wall ? 0.003
• Plasterboard stud wall ? 32
• Solid wooden 1 door ? 81
• Code 3 lead (1.3 mm) ? 0.1.

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Lead Apron Storage

• Always return to hanger
• Do not
• fold
• dump on floor and run trolleys over the top of
  them!!!
• X-ray will check annually
• But if visibly damaged, ask X-ray to check them.

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Physics lectures

• Tuesday or Thursdays
• 2pm start (please be prompt)
• Check the venue

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The End