THE DETERMINATION OF THE AVERAGE PATIENT SKIN DOSE AND ITS FACTORS AFFECTING IN CARDIAC CATHETERIZATION PROCEDURES

Abstract

The patient dosimetry for cardiac catheterization and its factors affecting in this study were determined using Dose Area Product (DAP) method. The skin dose was calculated from DAP meter readout and information from portal film determination. Factors affecting patient dose are fluoroscopy time, patient body mass index (BMI), kVp, mAs, experience of the cardiologists, number of frames and etc. The measurement was carried out from 73 patients who underwent the cardiac catheterization procedures examination such as Diagnostic Coronary Angiography (DCA), Cardiac intervention; Percutaneous Transluminal Coronary Angioplasty (PTCA)/stent and cardiac radiofrequency ablation at King Chulalongkorn Memorial Hospital. The result of the average patient skin dose from DCA was 9.52 cGy in tube A (Postero-Anterior) and 18.67 cGy in tube B (Lateral), PTCA/stent 35.95 cGy in tube A and 85.42 cGy in tube B and cardiac radiofrequency ablation 64.82 cGy for single plane. The patient skin dose is more dependent on the fluoroscopy time than other factors. The patient skin dose and the fluoroscopy time was well correlated for RF ablation (r= 0.90), PTCA/ stent (r= 0.83) and DCA (r=0.60). The average patient skin doses in this study were less than threshold dose of skin injury (2Gy). Only two patients received the dose higher than the threshold dose (2.12, 4.51 Gy) from cardiac radiofrequency ablation and cardiac interventional studies respectively. The benefit of this study are reported and established the patient skin dose in order to protect the patient from skin injury and increase the cardiologists, awareness for cardiac catheterization procedure.