Efficacy and User Experience of a Novel X-Ray Shield on Operator Radiation Exposure During Cardiac Catheterization: A Randomized Controlled Trial.

BACKGROUND: Radiation shielding is mandatory during cardiac catheterization, but there is a need to improve efficacy and ease of use. METHODS: The aim of the study was to assess the shielding effect and user feedback for a novel flexible multiconfiguration x-ray shield (FMX). The 0.5-mm Pb equivalent FMX can be selectively configured to accommodate for variations in patient morphology, access site, and type of procedure with maintained visualization, vascular access, and shielding. To evaluate efficacy, relative operator dose (operator dose indexed for given dose) was measured during 103 consecutive procedures randomized in a 1:1 proportion to the current routine setup or FMX+routine. User feedback was collected on function, relevance, and likelihood of adoption into clinical practice. RESULTS: Median relative operator dose was 3.63 µSv/µGy·m2×10-3 (IQR, 2.62-6.37) with routine setup and 0.57 µSv/µGy·m2×10-3 (IQR, 0.27-1.06) with FMX+routine, which amounts to an 84.4% reduction (P<0.001). For 500 procedures/year, this corresponds to an estimated yearly dose reduction from 3.6 to 0.7 mSv. User feedback regarding size, functionality, ease of use, likely to use, critical issues, shielding, draping, procedure time, vascular access, patient discomfort, and risk was 99% positive. No critical issues were identified. There was no significant difference in patient radiation exposure. CONCLUSIONS: The FMX reduces radiation exposure considerably. The FMX represents an effective and attractive solution for radiation protection that can easily be implemented in existing workflow. FMX has potential for general use with maintained visualization, vascular access, and shielding in routine cardiac catheterization.

Effect of an optimized X-ray blanket design on operator radiation dose in cardiac catheterization based on real-world angiography.

BACKGROUND: There is increasing concern and focus in the interventional cardiology community on potential long term health issues related to radiation exposure and heavy wearable protection. Optimized shielding measures may reduce operator dose to levels where lighter radioprotective garments can safely be used, or even omitted. X-ray blankets (XRB) are commercially available but suffer from small size and lack of stability. A larger XRB may reduce operator dose but could hamper vascular access and visualization. The aim of this study is to assess shielding effect of an optimized XRB during cardiac catheterization and estimate the potential reduction in annual operator dose based on DICOM Radiation Dose Structured Report (RDSR) data reflecting everyday clinical practice. METHODS: Data accumulated from 7681 procedures over three years in our RDSR repository was used to identify projection angles and radiation doses during cardiac catheterization. Using an anthropomorphic phantom and a scatter radiation detector, radiation dose to the operator (mSv) and patient (dose area product-DAP) was measured for each angiographic projection for three different shielding setups. Relative operator dose (mSv/DAP) was calculated and multiplied by DAP per projection to estimate effect on operator dose. RESULTS: Adding an optimized XRB to a standard shielding setup comprising a table- and ceiling-mounted shield resulted in a 94.9% reduction in estimated operator dose. The largest shielding effect was observed in left and cranial projections where the ceiling-mounted shield offered less protection. CONCLUSIONS: An optimized XRB is a simple shielding measure that has the potential to reduce operator dose.

Design optimization of a pixel-based range telescope for proton computed tomography.

PURPOSE: A pixel-based range telescope for tracking particles during proton imaging is described. The detector applies a 3D matrix of stacked Monolithic Active Pixel Sensors with fast readout speeds. This study evaluates different design alternatives of the range telescope on basis of the protons' range accuracy and the track reconstruction efficiency. METHOD: Detector designs with different thicknesses of the energy-absorbing plates between each sensor layer are simulated using the GATE/Geant4 Monte Carlo software. Proton tracks traversing the detector layers are individually reconstructed, and a Bragg curve fitting procedure is applied for the calculation of each proton's range. RESULTS: Simulations show that the setups with 4 mm and thinner absorber layers of aluminum have a low range uncertainty compared to the physical range straggling, systematic errors below 0.3 mm water equivalent thickness and a track reconstruction capability exceeding ten million protons per second. CONCLUSIONS: In order to restrict the total number of layers and to yield the required tracking and range resolution properties, a design recommendation is reached where the proposed range telescope applies 3.5 mm thick aluminum absorber slabs between each sensor layer.