The system of radiological protection aims to control radiation risks without unduly limiting the potential benefits for individuals and for society. The current International Radiation Basic Safety Standards (BSS) have expanded the requirements for justification of medical exposures and optimization of protection and safety in medicine. A substantial fraction of radiation imaging procedures is unjustified and does not provide a net benefit. Referral criteria for medical imaging are consensus statements based on the best available evidence, to assist decision making process when choosing the best imaging procedure for a given patient. Although they are advisory rather than compulsory, there should be good reasons to deviate from them. The optimization of protection in medical imaging means to deliver the the lowest possible radiation dose necessary to acquire adequate diagnostic data images.

Justification of procedures and optimization of protection are the two pillars of radiological protection in health care, and they are embedded in the notion of good medical practice. However, health professionals are not familiar with these principles and, in particular have a low awareness of radiation protection aspects of justification. A stronger collaboration between radiation protection and health care communities is needed to improve the radiation protection culture in the medical practice.

Justification of the use radiation for medical imaging of asymptomatic people

Decision making tools such as evidence-based clinical imaging referral guidelines can enhance justification of medical imaging in patients with clinical conditions (i.e. current or past signs and/or symptoms). In contrast, consensus still does not exist regarding criteria for justification of medical imaging of asymptomatic people outside approved population screening programmes, for individual health assessment (IHA). 

WHO convened an international expert consultation on 15-17 October 2014 in Munich, Germany, hosted by the BfS as a WHO Collaborating Centre to address the justification of the use of computed tomography (CT) in asymptomatic people for IHA. WHO organized an International Stakeholder Workshop on Justification of the Use of CT in for IHA of Asymptomatic People which was held on 26-28 September 2016 in Seoul, Korea, hosted by the Korean Society of Radiology. WHO also organized the seminar on “Imaging Asymptomatic People: are we doing more good than harm” during the International Conference on Preventing Overdiagnosis (POD2017) held in Quebec, Canada, in August 2017, and the  seminar on “Imaging asymptomatic people: a framework addressing clinical governance and regulatory compliance” during the International Conference on Preventing Overdiagnosis (POD2018) held in Copenhagen, Denmark, in August 2018. Building on the outcomes of those meetings, WHO developed guidance proposing a conceptual framework for justification of the use of CT in IHA.

The clinical value of medical use of radiation for the diagnosis and treatment of paediatric illness and injury is unquestionable. The benefits of radiological medical procedures far outweigh the radiation risks when these procedures are appropriately prescribed and properly performed. Justification of procedures and optimization of protection are particularly critical in children because:

• children are especially vulnerable to environmental threats, such as ionizing radiation;
• children are expected to have longer a life-span to develop long-term radiation-induced health effects; and
• when using ionizing radiation for medical imaging , such as CT scans, children might receive a higher radiation dose than necessary if the settings are not adjusted for their smaller body size.

Radiation risk communication in paediatric imaging

Health care providers need sufficient background, education and resources to communicate clearly and effectively about the benefits and risks of medical imaging procedures. Tools for radiation risk communication can support benefit-risk dialogue between health professionals, patients, and families to help them make informed decisions. WHO is conducting a project on radiation risk communication focused on paediatric imaging.

• 1st WHO International Workshop on Radiation Risk Communication in Paediatric Imaging: Geneva, Switzerland, September 2010) gathering 35 participants from 23 professional societies, international and regional organizations and United Nations (UN) agencies, with representatives of key stakeholders.
• 2nd WHO International Workshop on Radiation Risk Communication in Paediatric Imaging: December 2012, Bonn, Germany, gathering 56 participants from 19 countries and 12 international organizations, with representatives of key stakeholders. Workshop.
• WHO-WONCA workshop on the Role of Family Doctors in Communicating Radiation Risks in Paediatric Imaging: June 2013, Prague, Czech Republic.
• WHO-NIRS International Dialogue Seminar on Radiation Risk Communication for Medical Practitioners: December 2014 Tokyo, Japan.
• Bonn International Workshop on Radiation Risk Communication in Paediatric Imaging: December 2012. 

A tool on radiation risk communication to support benefit-risk dialogue in paediatric imaging

Patients and families should have access to risk-benefit discussions about paediatric imaging when, where, and in the way they need to best understand the information and to be able to use it for making informed choices. Accurate and effective radiation risk communication is also necessary between health care providers who request or perform radiological medical procedures in children. By enabling informed decision-making, effective radiation risk communication contributes to ensure the greatest possible benefit of paediatric imaging, at the lowest possible risk.

The document “Communicating radiation risks in paediatric imaging: Information to support healthcare discussions about benefit and risk” is intended to serve as a tool for health care providers to communicate known or potential radiation risks associated with paediatric imaging procedures, to support risk-benefit dialogue in health care settings.

The clinical value of medical use of radiation for the diagnosis and treatment of paediatric illness and injury is unquestionable. The benefits of radiological medical procedures far outweigh the radiation risks when these procedures are appropriately prescribed and properly performed. Justification of procedures and optimization of protection are particularly critical in children because:

• children are especially vulnerable to environmental threats, such as ionizing radiation;
• children are expected to have longer a life-span to develop long-term radiation-induced health effects; and
• when using ionizing radiation for medical imaging , such as CT scans, children might receive a higher radiation dose than necessary if the settings are not adjusted for their smaller body size.

Imaging for saving kids: the inside story about patient safety in paediatric radiology

A side event was co-organized by four Member States during the 68th World Health Assembly (May 2015, Geneva, Switzerland) to raise awareness about the importance of radiation safety and advocate for appropriate use of medical imaging in children. The meeting was co-facilitated by nine nongovernmental organizations in official relations with the WHO. Policy-makers, health-care providers, equipment manufacturers and patients came together to discuss the importance of multi-stakeholder partnerships to improve justification and optimization radiological procedures in children. Promotion of the Bonn Call for Action, implementation of the international radiation basic safety standards, as well as collaboration with stakeholders were highlighted as different means to improve safety and quality of patient care.

Improving radiation protection in paediatric interventional radiology 

Interventional radiology (IR) and cardiology (IC) are increasingly used in children as minimally invasive procedures that can replace more complex paediatric surgery options. WHO is conducting a project to enhance radiation safety culture  and improve optimization of protection and safety  in fluoroscopy-guided interventional practices in children in Latin America and the Caribbean (OPRIPALC project) including  establishment of diagnostic reference levels (DRLs) and training in radiation protection of health workers.