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Typical values for patient exposure in diagnostic X-ray applications

Recommendation by the German Commission on Radiological Protection

Adopted at the 337th meeting of the SSK on 29 April 2025

Can patient exposure in diagnostic X-ray applications be reduced by using typical values?

Why has the SSK addressed this topic?

In radiation protection, national diagnostic reference levels (DRLs) are used to optimise doses in diagnostic X-ray applications. However, DRLs are not available for all types of examinations. Certain technical procedures and clinical requirements are not covered by these reference levels. Additional typical values can be determined with less effort and could fill this gap.

What questions are addressed?

  • Can typical values also be determined and applied in addition to national DRLs?

  • How can dose data be collected and analysed to create such typical values?

What are the key messages?

  • The national DRLs established under radiation protection legislation and the procedure for their determination shall be retained.

  • To support further optimisation, additional dose data shall be collected locally, preferably using dose management systems (DMS).

  • For examination types for which no DRLs exist, the typical values derived from these dose data shall be provided.

  • In order to support the determination of typical values and to enable interregional comparisons, a nationwide standardized, automated process for recording dose data shall be introduced.

Abstract

Diagnostic reference levels (DRLs) are a radiation protection tool used for dose optimization in diagnostic X-ray applications in humans. In addition to the established national DRLs, which are determined and published by the Federal Office for Radiation Protection (BfS), local DRLs and typical values may also be implemented in accordance with the recommendations of ICRP Publication 135. They can be used for examinations not covered by national DRLs; they can also be generated and applied for various modalities or different clinical indications. This enables users to classify their dose values and thus optimize doses independently of the DRLs defined by the Radiation Protection Ordinance (StrlSchV).

This recommendation advocates the systematic collection, analysis, and utilization of dose data for the establishment of typical values.