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Ionising radiation

Last updated on 21 May 2019

Under the Ionising Radiation (Medical Exposure) Regulations 2017 and the Ionising Radiation (Medical Exposure) (Northern Ireland) Regulations 2018 (referred to as IRMER)  Research Ethics Committee (REC)  (as defined under IRMER) approval is required where participants are to be exposed to ionising radiation as part of their involvement in medical or biomedical, diagnostic or therapeutic, research. 

Research studies involving the administration of radioactive substances must also be approved by the Administration of RadioactiveSubstances Advisory Committee (ARSAC).

IRMER came into force on 6 February 2018. IRMER 2017 is applicable in England, Scotland and Wales, while IRMER 2018 is applicable in Northern Ireland.

The HRA provides a free eLearning module on research involving exposure to ionising radiation. 

Scope of IRMER

Procedures involving ionising radiation include, but are not limited to: 

  • general radiography, interventional imaging, CT scans, DXA scans, mammography and dental radiography
  • radiotherapy (including brachytherapy and therapy using unsealed sources)
  • administration of radioactive substances (e.g. nuclear medicine and PET/CT).

Procedures such as Magnetic Resonance Imaging (MRI) or ultrasound investigations do not involve ionising radiation and therefore IR(ME)R is not applicable to those procedures. 

Regulatory review

The REC’s ethical opinion will be informed by:

  • the whole burden from the research exposures, giving particular consideration to exposures that would be additional to exposure received by participants as part of normal clinical care if they opted not to participate in research
  • whether the research exposures are ethically acceptable
  • what the risks and burdens are which are involved in relation to the potential benefits
  • the description of risk in the participant information sheet
  • other risks associated with the study taking into consideration recognised variation, in routine clinical practice, between sites.

A favourable ethical opinion is required before the research may commence at any site.

The areas covered by the ARSAC review are stated in the ARSAC notes for guidance.

Preparation of IRAS documentation

In order to assist the REC in reaching its ethical opinion and ARSAC in deciding whether to issue approval, Part B Section 3 of the Integrated Research Application System (IRAS) application requires input from:

  • a lead Medical Physics Expert (MPE),  who performs a radiation dose/risk assessment for all the radiation exposures proposed in the protocol
  • a lead Clinical Radiation Expert (‘CRE), who assesses all radiation exposures at any site in the study and advises the Chief Investigator (CI) and the REC on the suitability and clinical justification for additional exposures.

For further information about how to apply to ARSAC/a REC please visit our 'approvals and amendments' section. Specific guidance about the MPE and CRE review is provided in the IRAS application form question specific guidance.

Information provided to participants

IRMER specifies that individuals are informed in advance of the risks of any ionising radiation exposures they receive. The lead MPE and CRE should ensure that any written information to be provided to participants about these risks is appropriate.

We have developed generic risk statements for use by the lead CRE and MPE in developing the Participant Information Sheet. Additionally there are generic risk statements for use in the IRAS form included in this guidance which will assist the REC in reaching its ethical opinion.

IRMER compliance at research sites

There is a legal requirement for the employer at the site where ionising radiation exposures are conducted to establish a governance framework to ensure compliance with IRM)R for research. The Lead MPE and CRE reviews in the IRAS form may be used to assist with this requirement, and in particular for the reviews conducted by MPEs and practitioners (under IRMER) at the site.

It is the site’s responsibility to confirm whether it can adhere to the research protocol.

Where a site cannot undertake the exposures specified in the protocol within a reasonable margin of the dose constraint specified in the MPE statement in Part B section 3, the site should consider their suitability to undertake the research. 

The local MPE should consider what constitutes a reasonable margin of the dose constraint based on the exposures specified, local and national diagnostic reference levels (DRLs) for the exposures where they may apply and the level of optimisation of the equipment being considered in making this judgement.  

It is expected that only in exceptional circumstances a site would not be able to take part due to inability to comply with the dose constraint. In the event that a local MPE suspects that not all exposures have been considered or there is an error in the calculation they should contact the sponsor.

For research programmes which include the administration of radioactive substances, the employer and the IRMER practitioner at the site are required to hold a licence which specifies the administration for the purpose of research. It is the responsibility of the employer and IRMER practitioner to ensure they hold an appropriate licence prior to any procedures taking place.

Radiation Assurance

As part of UK-wide work to streamline research, the HRA has implemented a Radiation Assurance service. 

This is designed to assist applicants in seeking the appropriate CRE and MPE experts to complete reviews in IRAS, assist CREs and MPEs in providing more consistent information within the reviews and thus minimise delays by identifying issues at an earlier stage, reducing duplication and providing a single point of contact for sponsors. 

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