“Dose reduction potential of using gold fiducial markers for kilovoltage image-guided radiotherapy”
Extract from abstract: This study aimed to evaluate the possibility of reducing the imaging dose for image-guided radiotherapy by using planar kilovoltage orthogonal imaging and [Gold Anchor] fiducial markers (kV-FM). We tested kilovoltage planar images under clinical imaging conditions for the pelvis (75 kVp, 200 mA, 50 ms) at a decreasing tube current (from 200 to 10 mA). The visibility of the kV-FM, aspects of image quality (spatial resolution, low contrast resolution), and the resultant image registration reproducibility were evaluated. The imaging doses with 200 and 10 mA were approximately 0.74 and 0.04 mGy. Regardless of the marker’s shape, the GA phantom ensured visibility even when the tube current was reduced to the minimum value (10 mA). The low contrast resolution was gradually decreased at less than 50 mA, but the spatial resolution did not change. Manual-registration could be achieved with an accuracy of within 1 mm, even when the imaging dose was reduced to 1/20 of the clinical imaging condition for the pelvis.
Article from The Journal of Applied Clinical Medical Physics, 2020