EuroSafe Imaging 2020
Performed at one institution, Not applicable, Retrospective, Quality assurance, Radiation safety, Physics, Fluoroscopy, Radioprotection / Radiation dose, Interventional vascular, Action 5 - Performance indicators for radiation protection management
R. M. Sanchez, E. Vano, J. I. Ten, P. Salinas, N. Gonzalo, J. Escaned, J. M. Fernández Soto
Description of activity and work performed
Measurement of patient and scatter dose were performed in three catheterization rooms dedicated to interventional cardiology. Two of the interventional laboratories are Allura Xper models and the third one is an Allura Clarity (all from Philips Healthcare). All three have the same image detector and X-ray tube and quite a similar generator. The main difference between the Allura Xper model and the Allura Clarity is that the latter has an additional functionality (hardware and software) that can provide an important patient dose reduction [3-10]. This dose reduction functionality requires the use of higher beam filtration, that has a default value of 0.4 mm Cu + 1 mm Al for fluoroscopy and cine. In the Xper model, the cine is delivered with no additional filtration and the fluoroscopy has (in our hospital) a default value of 0.9 mm Cu + 1 mm Al. When comparing these two different systems, from now on we will refer to the Xper model with no added filtration in cine as the “standard” system and to Clarity with a patient dose reduction capability and with 0.4 mm Cu + 1 mm Al of added filtration in cine as the “dose reduction” system.
Using the dose management system DoseWise Portal coupled with the DoseAware Xtend system (both from Philips HealthCare), the patient dose records from the radiation dose structured report (RDSR) are archived along with the occupational dose measurements from the occupational dose structured reports (ODSR) the electronic personal dosimeters model i3 (RaySafe, Sweden) used in the room (figure 1). These electronic personal dosimeter used for this study was located at the C-arm (figure 1) during routine practice recording a high sample of clinical procedures.
From the analysis of 341.047 radiation events it was observed that in the dose reduction system the 70% of the KAP was delivered with 0.4 mm Cu + 1 mm Al of added filtration, while in the standard system the 70% of the KAP was delivered with no added filtration.
Figure 2 shows the ratio Hp(10)/KAP per procedure, graphed with boxes, for the two types of systems discussed in this investigation: the “dose reduction” with high filtration system (4342 cases with a default added filtration of 0.4 mm Cu in cine) and the “standard” with low filtration system (667 cases with no added filtration in cine). The average ± standard deviation resulted in 7±2 μSv·Gy-1cm-2 for the “standard” and 13±3 μSv·Gy-1cm-2 for the “dose reduction” system (p<0.001).
Figure 3 shows the cumulative KAP and Hp(10) per procedure for both models of X-ray systems. The median for the cumulative Hp(10) per procedure measured at the C-arm was quite similar in both systems: for the standard and dose reduction system, the median was 346 and 302 μSv respectively, while the median KAP was two fold in the standard system, 53 vs 25 Gy·cm2.