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Radiation - Medical Exposure

Nuclear medicine technician Clifton West dispensing a patient injection behind lead shielding
Nuclear medicine technician Clifton West dispensing a patient injection behind lead shielding

Radiation Doses in Nuclear Medicine

Ionising radiation, such as that used in Nuclear Medicine tests, can cause damage to human cells. Damage to DNA can lead to chromosome breakage which may cause mutations when the cell replicates, possibly leading to cancers, or hereditary effects, demonstrated in future offspring after the exposure.

The International Committee on Radiation Protection (ICRP60) states that the probability of contracting fatal cancer from a Nuclear Medicine test is approximately 1 in 10000, and the probability of severe hereditary effects in future generations is 13 in every 1000 births. The natural risk of developing fatal cancer is 1 in 4 (Office for National Statistics 2006), and that of congenital abnormalities is approximately 11 in every 1000 births (Botting and Physick 2004), therefore the risk from having one of our tests is not statistically significant compared with the natural occurrence. To put this in perspective the dose from a Nuclear Medicine test is comparable with the annual dose from natural sources, and the risk is less than the annual risk of being involved in a fatal road accident. 


Legislation is set in place to protect people from unnecessary exposure to radiation.

ARSAC certificate Holders and The Medicines (Administration of Radioactive Substances) Regulations (MARS) 2006

The MARS Regulations were implemented to protect patients and volunteers from unnecessary exposure to radiation. Any doctor or dentist wanting to administer radioactive medicinal products for therapy, diagnosis or research is required to hold a certificate, obtained from the Administration of Radioactive Substances Advisory Committee (ARSAC) under the MARS Regulations. ARSAC publish their Notes for Guidance  (2006) as a guide to the safe practice of clinical nuclear medicine and the administration of radiopharmaceuticals. These include details of the MARS regulations, advice on diagnosis, treatment and research, and dose reduction methods, paediatric investigations, dose calculation techniques and diagnostic reference levels. The Notes for Guidance have no legal status, with the exception of Diagnostic Reference Levels (DRLs), which are the amounts of radiopharmaceuticals recommended for obtaining a useful diagnosis whilst keeping the patient's radiation dose as low as reasonably practicable.

IR(ME)R 2000

IR(ME)R 2000 legislation covers patients undergoing medical exposure to ionising radiation. It is enforced under the Health and Safety Act 1974. IR(ME)R 2000 covers medical exposures for diagnosis, occupational health surveillance, health screening and voluntary participation in research programs and protects patients by ensuring justification, optimisation and limitation of radiation exposure. These regulations require employers undertaking medical exposures to establish diagnostic reference levels (DRLs) and to undertake appropriate reviews if these are consistently exceeded. IR(ME)R also defines the roles of practitioners, operators and referrers:

  • The referrer is to provide the practitioner with sufficient medical information for the practitioner to justify the exposure
  • The practitioner is responsible for justification of the exposure, and may refuse the request if there is insufficient evidence to suggest the exposure is necessary
  • The operator is responsible for the practical aspects of the examination, for example, undertaking the scan

All medical exposures must be justified and authorised by a practitioner, or approved by the local ethics committee for research exposures. The employer is required to have a number of procedures in place to ensure patient safety. These include procedures for patient identification and a procedure for identifying pregnant or breastfeeding women. UHL IR(ME)R Employers Procedures are available through the hospitals internal website, INsite.

Other relevant legislation

The Ionising Radiations Regulations 1999 (IRR 99)

The Radioactive Substances Act 1993 (RSA)

The Carriage of Dangerous Goods Act 2007 (CDG)

The Medicines Act 1968

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