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A Proton Computed Tomography Demonstrator for Stopping Power Measurements

Medical Physics 2022-12-21 v1

Abstract

Particle therapy is an established method to treat deep-seated tumours using accelerator-produced ion beams. For treatment planning, the precise knowledge of the relative stopping power (RSP) within the patient is vital. Conversion errors from x-ray computed tomography (CT) measurements to RSP introduce uncertainties in the applied dose distribution. Using a proton computed tomography (pCT) system to measure the SP directly could potentially increase the accuracy of treatment planning. A pCT demonstrator, consisting of double-sided silicon strip detectors (DSSD) as tracker and plastic scintillator slabs coupled to silicon photomultipliers (SiPM) as a range telescope, was developed. After a significant hardware upgrade of the range telescope, a 3D tomogram of an aluminium stair phantom was recorded at the MedAustron facility in Wiener Neustadt, Austria. In total, 80 projections with 6.5x10^5 primary events were acquired and used for the reconstruction of the RSP distribution in the phantom. After applying a straight-line approximation for the particle path inside the phantom, the most probable value (MPV) of the RSP distribution could be measured with an accuracy of 0.59%. The RSP resolution inside the phantom was only 9.3% due to a limited amount of projections and measured events per projection.

Keywords

Cite

@article{arxiv.2106.12890,
  title  = {A Proton Computed Tomography Demonstrator for Stopping Power Measurements},
  author = {Felix Ulrich-Pur and Thomas Bergauer and Alexander Burker and Albert Hirtl and Christian Irmler and Stefanie Kaser and Florian Pitters},
  journal= {arXiv preprint arXiv:2106.12890},
  year   = {2022}
}

Comments

Preprint submitted to the open-access Journal of Physics: Conference Series. (TIPP2021 conference proceedings). IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it