Gantry-free cone-beam CT (CBCT) allows for ultra-high-resolution (UHR) upper extremity imaging in a comfortable tableside position. The aim of this study was to assess the organ-specific radiation burden and the effect of dedicated lead shielding in the UHR-CBCT of the wrist and elbow. A modified Alderson-Rando phantom was scanned with the tableside UHR-CBCT mode of a twin robotic X-ray system employing identical scan parameters for wrist and elbow imaging.
View Article and Find Full Text PDFRationale And Objectives: This study investigates the dose burden of photon-counting detector (PCD) lung CT with ultra-high-resolution (UHR) and standard mode using organ-based tube current modulation (OBTCM).
Materials And Methods: An anthropomorphic Alderson-Rando phantom was scanned in UHR and standard mode with and without OBTCM on three dose levels (IQ 5, 20, 50). Effective radiation dose was determined by thermoluminescent dosimetry in 13 measurement sites and compared with the calculated effective dose derived from the dose-length product.
Cone-beam computed tomography (CBCT)-based online adaptation is increasingly being introduced into many clinics. Upon implementation of a new treatment technique, a prospective risk analysis is required and enhances workflow safety. We conducted a risk analysis using Failure Mode and Effects Analysis (FMEA) upon the introduction of an online adaptive treatment programme (Wegener et al.
View Article and Find Full Text PDFMotivation: Online adaptive radiotherapy with Ethos is based on the anatomy determined from daily cone beam computed tomography (CBCT) images. Dose optimization and computation are performed on the density map of a synthetic CT (sCT), a deformable registration of the initial planning CT (pCT) onto the current CBCT. Large density changes as present in the lung region are challenging the system.
View Article and Find Full Text PDFCranial stereotactic irradiations require accurate reproduction of the planning CT patient position at the time of treatment, including removal of rotational offsets. A device prototype was evaluated for potential clinical use to correct rotational positional offsets in image-guided radiotherapy workflow. Analysis was carried out with a prototype device "RPS head" by gKteso GmbH, rotatable up to 4° in three dimensions by hand wheels.
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