A study presented at the Society of Interventional Radiology’s (SIR’s) 2015 annual scientific meeting reveals that a new angiographic imaging platform (AlluraClarity, Philips Healthcare) maintains similar procedure time as a current C-arm imaging platform (Allura, Philips), yet with substantially reduced radiation exposure for uterine artery embolization procedures.
These findings have particular relevance for the many women undergoing uterine artery embolization who are of child-bearing age, as well as for the interventional radiology staff present in the room during the procedure.
Ruediger Egbert Schernthaner, a member of Jean-Francois Geschwind’s research team at the Johns Hopkins University, Baltimore, USA, set out to quantify the radiation exposure reduction of a new C-arm imaging platform for women with symptomatic uterine fibroids who were treated with uterine artery embolization.
In this ongoing prospective trial, twenty nine consecutive patients with symptomatic uterine fibroids were treated either on the new dose reduction imaging platform (n=15; AlluraClarity) or the reference imaging platform (n=14; Allura). X-ray dose logging was performed using a dedicated Radiation Dose Structured Reporting (RDSR) server.
The new system uses optimised acquisition parameters to lower the radiation exposure and real-time image processing algorithms such as noise reduction, temporal averaging and automatic pixel shift to restore the image quality.
Air kerma, the radiation exposure in free air before reaching the body, dose area product, the absorbed radiation dose multiplied by the area irradiated and acquisition time for digital fluoroscopy and digital subtraction angiography were recorded. The body mass index of patients was also noted. The unpaired t-test and Wilcoxon rank-sum tests were used to assess statistical differences between the platforms.
The investigators found that there was no difference in body mass index between the two patient cohorts. “Additionally, there was no significant difference in digital fluoroscopy or digital subtraction angiography time between the new and reference platforms, indicating that the procedure courses were similar between the two cohorts,” Schernthaner said.
“Compared to the reference platform, the new platform significantly reduced the cumulative air kerma and dose area product by 57% and 66%, respectively (p<0.001 for both). Specifically, dose area product for digital fluoroscopy and digital subtraction angiography decreased by 39% (111.2 vs. 181.9 Gy*cm2, p=0.04) and 80% (65.5 vs. 320.5 Gy*cm2, p<0.001), respectively,” he reported.
“The reduction of radiation exposure to only 20% of the standard system during digital subtraction angiography is especially important when considering that a number of interventional radiologists reported during the SIR meeting that they restrict the use of digital subtraction angiography in an attempt to lower the radiation exposure, but at the cost of an increased risk of non-target embolization,” Schernthaner explained.
Schernthaner is a senior physician at the Medical University of Vienna, Vienna, Austria and a visiting scientist supported by the Max Kade Foundation at the Johns Hopkins University, Baltimore, USA.