Coronary angiography and percutaneous transluminal coronary angioplasty procedures: Evaluation of patients' maximum skin dose using Gafchromic films and a comparison of local levels with reference levels proposed in the literature.

The aim of this study was to evaluate the maximum skin dose (MSD) in patients undergoing interventional cardiology procedures, obtaining local reference levels and comparing these with the reference levels proposed in the literature. The patients' MSD was measured using Gafchromic XR type R films. In order to evaluate reference levels, the number of images acquired, the fluoroscopy times and the KAP(TOTAL) were recorded for each procedure. For the evaluation of the MSD, 8 coronary angiography (CA) and 16 percutaneous transluminal coronary angioplasty (PTCA) procedures, carried out in the period from May to June 2008, were analyzed. For the CA procedures the MSD values were below 0.5 Gy. For the PTCA procedures, we found a fairly good correlation between fluoroscopy time and MSD (r = 0.80, p = 0.0002) and between MSD and WFP (r = 0.863, p < 0.0001); there was a strong correlation between KAP(TOTAL) and MSD (r = 0.904, p <0.0001). Since the correlation between KAP(TOTAL) and MSD is more striking than that with fluoroscopic time and the WFP, KAP measurements are suitable for online skin dosimetry and may, therefore, be used to avoid radiation-induced skin injuries. A MSD greater than 3 Gy occurred in only one procedure. For calculus of the local reference levels, we extended the data-gathering to 30 procedure CA and to 40 PTCA: we compared local practice with that in other centers using the guidance levels proposed by Balter et al. Our median KAP values were below these proposed guidance levels; our mean KAP values were above these proposed action levels. From a first application of the proposed reference levels, it appears that, according to the recommendations of Balter et al. an investigation into local practice is not necessary.