Updating national diagnostic reference levels for adult cardiac interventional procedures in Switzerland

Diagnostic reference levels (DRLs) have been proven to be a useful tool for optimizing patient radiation exposure. National DRLs (NDRLs) are defined based on data from a representative sample of the healthcare facilities in a particular country. This project presents the survey to update the NDRLs for cardiac interventional procedures in Switzerland. Healthcare facilities performing cardiac procedures in Switzerland were asked to provide radiation dose data for adult cardiac interventional procedures performed over the course of one year. The dataset included the procedure name and the corresponding air kerma area product, air kerma at the reference point, fluoroscopy time and number of cine acquisitions. Thirty-five healthcare facilities (95% of the total) provided data. The procedures were grouped into 11 electrophysiology procedures, 4 cardiac catheterization procedures, and 3 structural heart procedures. For each healthcare facility and radiation quantity, the median values were calculated. Updated NDRLs were determined as the 75th percentile of the distribution of these median values. For example, the updated NDRL for air kerma area product was set at 24 Gy∙cm² for coronary angiography and at 2 Gy∙cm² for pacemaker implantation, reflecting a substantial reduction from the prior NDRL values of 50 and 30 Gy∙cm², respectively. These new NDRL values are substantially lower than the previous ones, highlighting the importance of conducting regular updates to accommodate continuous patient dose optimization of and technological advancements.