The harmful effects of radiation are well established. Nevertheless, it is generally accepted that the use of ionising radiation in medicine provides benefits that, overall, far outweigh the potential risks.

When new procedures or technologies are introduced, their benefits should be assessed. This is referred to as second-level justification. Third-level justification is the process undertaken when deciding whether the use of radiation is justified for an individual patient.

The Heads of the European Radiological Protection Competent Authorities (HERCA) have published guidance on the implementation of justification in medicine:

HERCA Position Paper: Justification of Individual Medical Exposures for Diagnosis

Appropriate procedures for the justification of medical exposures are one of the most effective means of reducing radiation exposure to individual patients and to the patient population as a whole.

The guidance addresses the roles and responsibilities of legislators, regulatory authorities and healthcare professionals, and emphasises the importance of ensuring that justification is established before a medical exposure takes place, whether for an examination or treatment. Documented procedures and work instructions should be in place to demonstrate that justification has been carried out for each individual medical exposure.

The following elements should be included, as appropriate:

• sufficient information on the patient's clinical condition relevant to the requested examination;

• the clinical question(s) to be addressed;

• information on previous or concurrent examinations, where relevant;

• a decision on the appropriate imaging procedure to be undertaken, taking into account alternative procedures that do not involve exposure to ionising radiation; and

• traceability of the above elements to the referrer and the practitioner responsible for the justification.

As part of a joint initiative by European radiation protection authorities to monitor the implementation of justification, six steps in the imaging pathway will be examined:

Justification is addressed in:

• Act on Radiation Protection (44/2002), Article 15.

• Regulation on Radiation Protection concerning the Use of Radiation-Emitting Equipment that Produces Ionising Radiation (1299/2015), Articles 23, 33 and 52.

• Regulation on Radiation Protection in the Use of Unsealed Radioactive Sources (809/2003), Articles 61, 66 and 79.

See also: Use of Radiation in Medicine: Focus on Justification in 2026