Commissioning of CT Simulator-Acceptance Testing and Quality Assurance

Authors: Priya Jacob

DOI: https://doi.org/10.5281/zenodo.14945265

Short DOI: https://doi.org/g86n8f

Country: USA

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Abstract: This study evaluated the clinical use of a newly installed computed tomography (CT) simulator (GE Hangwei Medical Systems Co. Ltd, China) in the Department of Radiation Oncology (Figure 3). Licensing was granted by the Atomic Energy Regulatory Board (AERB), Government of India3. A pencil ionization chamber connected to a suitable electrometer, along with a head/body phantom, was used to measure doses in the axial and peripheral cavities of the phantom for typical techniques.
Image quality parameters such as the Hounsfield unit (HU) value of water, noise level, homogeneity, presence of artifacts, spatial resolution, contrast, and slice thickness were assessed using a CT performance phantom. All test items were evaluated to ensure they met the required tolerance levels. CT calibration curves, representing the relationship between CT number and relative electron density, were obtained for dose calculations in the treatment planning system. The positional accuracy of the lasers was also verified. The volume CT dose indices (CTDIvol) were 15.74 mGy for the head phantom and 8.11 mGy for the body phantom. The HU accuracy, noise level, and homogeneity for the CT simulator were -2 HU, 10% of the specified value, and 1 HU, respectively. A high contrast resolution test phantom was used to assess spatial resolution, with the smallest resolvable bar/hole pattern being 0.6 mm (8.3333 lp/cm). The CT simulator demonstrated comparable performance and was deemed acceptable for clinical use.

Keywords: Computed Tomography, CT simulator, Acceptance test, Volume CT Dose Index (CTDIvol), Radiotherapy Planning, Image Quality Evaluation, Radiation Oncology

Paper Id: 232181

Published On: 2023-03-08

Published In: Volume 11, Issue 2, March-April 2023

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