title: Entrance skin dose during radiofrequency catheter ablation for tachyarrhythmia: a multicenter study.
abstract: BACKGROUND
  To assess the entrance skin dose (ESD) during radiofrequency catheter ablation procedures for tachyarrhythmia including atrial fibrillation (Af).
  
  
  METHODS
  This study focused on 99 consecutive patients who underwent procedures for tachyarrhythmia (Af; n = 34, non-Af; n = 65) in three institutions. The non-Af group included atrial flutter, atrial tachycardia, paroxysmal supraventricular tachycardia, ventricular tachycardia, ventricular premature contraction, atrial premature contraction, atrioventricular nodal reentry tachycardia, and Wolff-Parkinson-White syndrome. In two of the three institutions, the procedures were performed for both Af and non-Af. The ESDs were measured using 100 radiosensitive indicators attached to the back of each patient's jacket at 5-cm intervals. For statistical analyses, multiple regression analysis (the dependent variable, Max-ESD; and the independent variables, dose area product [DAP], total fluoroscopic time [TFT], body mass index, etc.), Pearson's correlation test, and the Mann-Whitney test were employed.
  
  
  RESULTS
  The overall averages for the TFTs, the DAPs, and the Max-ESDs were 49.9 ± 28.2 minutes, 71.2 ± 73.7 Gy cm(2) , and 0.57 ± 0.51 Gy, respectively. DAP was positively related to the Max-ESD and was significant in stepwise multiple regression analysis (P < 0.0001). There was a significant association between TFT and Max-ESD in five of the six kinds of angiographic unit, and between DAP and Max-ESD in all three systems with available DAP measures. In one institution, TFT, DAP, and Max-ESD differed significantly between the Af and non-Af groups (P = 0.0002, P < 0.0001, and P < 0.0001).
  
  
  CONCLUSIONS
  During the cardiac catheter ablation, ESDs of only a few patients exceeded the thresholds of radiation skin injuries, and the DAP proved useful to estimate each patient's Max-ESD.
authors: Department of Radiology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan. kidouchi-tky@umin.ac.jp
authors: Takashi
authors: T
authors: Kidouchi
authors: Shigeru
authors: S
authors: Suzuki
authors: Shigeru
authors: S
authors: Furui
authors: Haruo
authors: H
authors: Mitani
authors: Junichi
authors: J
authors: Nitta
authors: Kunihiro
authors: K
authors: Matsumoto
authors: Kuni
authors: K
authors: Ohtomo