Accurate assessment of patient effective radiation dose and associated detriment risk from radiofrequency catheter ablation procedures

Background-Radiofrequency (RF) cardiac catheter ablation procedures may req uire extended fluoroscopic exposure resulting in elevated radiation risk. T he aim of the present study was to accurately establish RF ablation radiati on risk levels and to provide means for accurate patient risk estimation fr om studies performed in any electrophysiology laboratory. Methods and Results-Fluoroscopy required during cardiac ablation was classi fied into 4 types identified by beam orientation and irradiated tissue: (l) posteroanterior exposure during catheter advancing from the groin to the he art, (2) posteroanterior heart exposure, (3) left anterior oblique heart ex posure, and (4) right anterior oblique heart exposure. The duration of each exposure was monitored in 24 patients undergoing RF cardiac ablation, Dose per minute of fluoroscopy was measured at 15 organs/tissues for each proje ction with the use of anthropomorphic phantom and thermoluminescence dosime try, The effective dose rate was 219, 144, 136, and 112 mu Gy/min for groin -to-heart posteroanterior, posteroanterior, left anterior oblique, and righ t anterior oblique exposure, respectively. A typical ablation procedure res ults in a total effective dose of 8.3 mSv per hour of fluoroscopy, The aver age excess of fatal cancers was estimated to be 650 and 480 per million pat ients undergoing RF ablation requiring 1 hour of fluoroscopy fur US and UK populations, respectively. The average risk for genetic defects was determi ned to be 1 per million births. Conclusions-Radiation risk from RF cardiac ablation is moderate compared wi th other complications, but it may highly exceed radiation risk from common radiological procedures. Efforts should be made toward minimization of pat ient radiation risk from RF ablation procedures.