Current status of diagnostic reference levels in interventional cardiology.

Interventional cardiology provides undisputable benefits for patients but uses a substantial amount of ionising radiation. The diagnostic reference level (DRL) is the tool recommended by the International Commission on Radiological Protection to optimise imaging procedures. In this work, a review of studies dealing with radiation dose or recommending DRL values for interventional cardiology since 2010 is presented, providing quantitative and qualitative results. There are many published papers on coronary angiography and percutaneous coronary intervention. The DRL values compiled for different continental regions are different: the DRL for coronary angiography is about 35 Gy·cm2 for Europe and 83 Gy·cm2 for North America. These differences emphasise the need to establish national DRLs considering different social and/or economic factors and the harmonisation of the survey methodology. Surveys with a large amount of data collected with the help of dose management systems, provide more reliable information with less chance of statistical bias than those with a small amount of data. The complexity of procedures and improvements in technology are important factors that affect the radiation dose delivered to patients. There is a need for additional data on structural and electrophysiological procedures. The analysis of paediatric procedures is especially difficult because some studies present results split into age bands and others in weight bands. Diagnostic procedures are better described, but there is a great variety of therapeutic procedures with different DRL values (up to a factor of nine) and these require a dedicated review.