DÄ internationalArchive27/2008Radiation Protection in Diagnostic Radiology: Only Trained Staff Defines Indication

Correspondence

Radiation Protection in Diagnostic Radiology: Only Trained Staff Defines Indication

Dtsch Arztebl Int 2008; 105(27): 498. DOI: 10.3238/arztebl.2008.0499a

Bockisch, A; Laniado, M

LNSLNS In our capacity as the presidents of the German Society of Nuclear Medicine and the German Radiological Society, we wish to comment on the article by Shannoun and colleagues.
Examinations in radiology and nuclear medicine are not only an "accepted part of clinical practice," but are often the vital prerequisite to reach the final diagnosis. The different units of energy dose D (Gy) and equivalent dose H (Sv) were not chosen so as to "avoid confusion." The actually relate to differently defined parameters.
We disagree with the authors' statement, that "the radiation exposure of patients during comparable investigations can vary by several orders of magnitude." For example, radiation exposure of posterior-anterior chest radiography, is about 0.02 mSv. If it were one order of magnitude higher, the effective dose would be 0.2 mSv whereas several orders of magnitude would mean a factor 100, i.e. an effective dose of 2 mSv – an unthinkable radiation exposure with state-of-the-art equipment.
Reference values in nuclear medicine are by no means "standard values which must be complied with." With an appropriate indication they may even be exceeded, granted that the dose is documented.
The legal responsibility for the choice of imaging method with ionizing radiation can only be taken over by the referring physician if he or she has permission according to radiation protection regulations (Röntgenverordnung). In any other scenario, the radiologist (expert in nuclear medicine) is responsible for what is called justifying indication. This may result in a change to the requested examination if another imaging method is more suitable for diagnosis and/or results in less radiation exposure.
The term "radiation exposure" (Strahlenexposition) should be preferred to "radiation burden" (Strahlenbelastung). Sentences such as "Direct dose-dependent radiation damage is extremely rare in X-ray diagnosis. At most, stochastic effects are observed" and "It is now assumed that there is no threshold under which damage is absolutely excluded" require further comment. Deterministic effects do not occur if diagnostic procedures are applied along well established guidelines. Stochastic effects, by definition, cannot be excluded, but cannot be proven in practice, since it is impossible to recognize radiation reactions below a dose of 100 mSv. DOI: 10.3238/arztebl.2008.0499a

Prof. Dr. med. Dr. rer. nat. Andreas Bockisch
Präsident der Deutschen Gesellschaft für Nuklearmedizin (DGN)
Universitätsklinikum
Klinik für Nuklearmedizin
Hufelandstr. 55, 45122 Essen, Germany

Prof. Dr. med. Michael Laniado
Präsident der Deutschen Röntgengesellschaft (DRG)
Universitätsklinikum Carl-Gustav-Carus der TU
Institut und Poliklinik für Radiologische Diagnostik
Fetscherstr. 74, 01307 Dresden, Germany