Joint IIRRT / IAPM position paper on international guidance on the use of patient contact radiation shielding

On review and evaluation of the international guidance [1-3) on the revised use of patient contact radiation shielding, the Irish Institute of Radiography and Radiation Therapy and the Irish Association of Physicists in Medicine are advocating for the adoption of these recommendations in Ireland.

 

Diagnostic Radiographers perform a range of imaging studies to facilitate diagnosis and follow up of disease processes within clinical settings. Many of these studies utilise ionising radiation and carry an associated risk to those exposed. Radiographers are highly trained in the area of radiation protection to ensure all medical exposures are justified and delivered using the lowest possible radiation dose, in compliance with the ALARA principle. It has been common practice to place radiation shielding directly on patients to reduce radiation doses to particular radiosensitive organs. The British Institute of Radiology, in conjunction with IPEM, RCR, SCoR, SRP and Public Health England, have published ‘Guidance on using shielding on patients for diagnostic radiology applications’ [2] recommending the cessation of this practice for the majority of examinations/procedures and supported such recommendations with analysis of literature and research. The American Association of Physicists in Medicine, supported by the American College of Radiology (ACR)[1], and a European consensus group[3], encompassing  the European Federation of Organisations for Medical Physics, European Federation of Radiographer Societies, European Society of Radiology, European Society of Paediatric Radiology, EuroSafe Imaging, European Radiation Dosimetry Group (EURADOS), and European Academy of DentoMaxilloFacial Radiology (EADMFR)  have also published similar guidance of the use of patient contact shielding.

It is the opinion of the IIRRT and the IAPM that these guidelines should be accepted and adopted into practice in Ireland but are cognisant of the variance in current practice and resources and the limitations of enacting the measures recommended in their entirety. While we are recommending a change to current practice, it is important to note that this can only be implemented if the core principles of radiation protection are practiced for each and every examination using ionising radiation.

This includes, but is not limited to:

  • justification and optimisation of examinations
  • correct and adequate collimation
  • careful selection of exposure settings and protocols
  • correct positioning
  • utilising evidence based practice
  • maintaining CPD for Practitioners

 

The cessation of patient contact shielding can also only be adopted if the Undertaking, Designated Manager, Practitioner and other relevant personnel can be assured that the equipment is subject to a rigorous and regular quality assurance programme involving Medical Physics Experts, manufacturers and Practitioners. This should ensure that the equipment is operating to the highest safety standards and Practitioners can have confidence in the radiation doses delivered by the equipment.

 

As with all changes to practice involving ionising radiation, under SI 256 of 2018 [4], the cessation of the use of lead shielding should first be discussed by the local Practitioners and Medical Physics Experts before being discussed and approved by the Radiation Safety Committee and the Undertaking. The change of practice can then be embedded in local protocol and policy as necessary.

Under SI 256 of 2018, all patients undergoing a medical exposure to ionising radiation should be provided with adequate information relating to the benefits and risks associated with the radiation dose. The omission of lead shielding should be included in this information to the patient and the rationale behind not using lead shielding, including the potential risks of shielding itself from risk of artefacts on the image to potential infection control issues from repeated usage. The information should seek to alleviate any concerns and educate the patients about this change to historical practice.

This scope of this position paper is specific to patient contact radiation shielding.  Guidance on the cessation of shielding for Carers and Comforters is not within the scope and falls under separate guidance.

It is acknowledged that the adoption of and adherence to these guidelines may be difficult in particular special circumstances such as the area of paediatric radiography and imaging of the pregnant patient.

 

Paediatric patients:

Imaging of paediatrics carries an increased risk of patient movement and errors with lead shielding placement, leading to a risk of the shielding entering the primary beam or repeat exposures due to the lead obscuring anatomy, which in turn would increase the radiation dose to the patient. With this in mind, lead shielding is not recommended for paediatric patients for x-ray examinations.

Children attending for general x-ray examinations do so in the company of a parent / guardian. The parent or guardian is treated as a member of the public and wears a lead apron to limit their radiation exposure during the examination. The fact the parent or guardian wears shielded PPE, while their child does not, can lead to concerns regarding the radiation dose to areas of the patient’s body outside the imaged anatomy. Studies have shown that the radiation dose falls to less than 1% within 2.5cm of the radiation field[2] and additional shielding outside more than 5 cm from the primary beam is likely to have a negligible effect on the radiation dose received[5].

It is, however, important that staff are able to articulate this information to parents/guardian to help alleviate any concerns they may have regarding their child’s radiation exposure.

 

Pregnant patients

As per the international published guidelines, lead protection shielding should not be used as a means of reassurance. Instead, communication with the patient as to the risks/benefits of the examination should be key to the discussion with the patient. Justification of ionising radiation procedures on pregnant patients remains the main tool for dose reduction in this cohort.

 

Conclusion

As outlined, the IIRRT and IAPM jointly recommend the local adoption of the recommendations by the international radiation protection community on the cessation of patient contact shielding for diagnostic radiology. It is recommended that local policies and protocols should be updated to reflect the change in practice before it is enacted clinically. The IIRRT and IAPM recommend that education of patient facing personnel is intrinsic in the adoption of these guidelines and should form a key aspect of the local implementation.

 

References

  1. American Association of Physicists in Medicine (2019) PS 8-A – AAPM Position Statement on the Use of Patient Gonadal and Fetal Shielding , April 2-3, 2019 AAPM Board of Directors Meeting Minutes [Available from http://aapm.org/org/policies]
  2. British Institute of Radiology (2020) Guidance on using shielding on patients for diagnostic radiology applications, London England.
  3. Hiles P, Gilligan P, Damilakis J, Briers E, Candela-Juan C, Faj D, Foley S, Frija G, Granta C, de las Heras Gala H, Pauwels R, Sans Merce M, Simantirakis G, Vano E (2022) European consensus on patient contact shielding, Physica Medica Vol 96(2022), pg 198-203
  4. Government of Ireland (2018). European Union (Basic Safety Standards for Protection against dangers from medical exposure to Ionising Radiation) Statutory Instrument 256 of 2018. Irish Statute Book. Available from http://www.irishstatutebook.ie/eli/2018/si/256/made/en/print?q=256&years=2018. Last accessed July 12th
  5. ICRP, 2013. Radiological protection in paediatric diagnostic and interventional radiology. ICRP Publication 121. Ann. ICRP 42(2).