[Multicenter Survey on Radiation Dose of Cardiac Intervention]

We conducted a nationwide survey of multiple institutions and collected data of various interventional procedures in the field of cardiology. Included in the analysis were 126 institutions, 381 X-ray systems, and 805 protocols. The dose values were compared with the Japanese diagnostic reference levels (DRLs) 2015. Fluoroscopy time, air kerma at the patient entrance reference point (K_{a, r}), and air kerma-area product (P_KA ) were analyzed for various interventional procedures in 5,734 cardiology patients. The fluoroscopic dose rate (FDR) for pulmonary vein isolation (PVI) was less than half that of the 75th percentile of the Japanese DRLs 2015. The 75th percentiles of fluoroscopy time, K_{a, r}, and P_KA for the respective interventional procedures were as follows: 11.0 min, 735 mGy, and 64 Gy･cm² for diagnostic coronary angiography (CA); 13.2 min, 839 mGy, and 75 Gy･cm² for CA + left ventriculography; 34.4 min, 1,810 mGy, and 148 Gy･cm² for percutaneous coronary intervention (PCI) excluding chronic total occlusion; 80.1 min, 4,338 mGy, and 312 Gy･cm² for PCI for chronic total occlusion; 74.4 min, 833 mGy, and 90 Gy･cm² for PVI; and 34.0 min, 795 mGy, and 94 Gy･cm² for transcatheter aortic valve implantation, respectively. In assessing dose values in interventional radiology, the difficulty of the technique needs to be considered, and the DRL values for FDR, fluoroscopic time, K_{a, r}, and P_KA for each interventional procedure are considered necessary when reassessing or updating DRLs.