Nuclear Technology and Radiation Protection (Jan 2021)

Assessment of computed tomography simulators used in radiotherapy treatment planning in Serbia, Croatia and Bosnia and Herzegovina

  • Petrović Borislava S.,
  • Faj Dario Z.,
  • Marković Mladen B.,
  • Tot Arpad A.,
  • Marjanović Milana S.,
  • Kasabašić Mladen D.,
  • Gencel Ivan V.,
  • Paunović Dragomir R.,
  • Stanković Jelena V.,
  • Krestić-Vesović Jelena,
  • Mišković Ivana M.,
  • Čičarević Koča B.,
  • Bibić Juraj I.,
  • Budanec Mirjana S.,
  • Kralik Ivana T.,
  • Galić Stipe J.,
  • Hrepić Darijo S.,
  • Ibrišimović Lejla A.,
  • Davidović Jasna Đ.,
  • Kolarević Goran D.

DOI
https://doi.org/10.2298/NTRP201118009P
Journal volume & issue
Vol. 36, no. 1
pp. 97 – 106

Abstract

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The purpose of this work was to evaluate computed tomography simulators used in radio-therapy treatment planning in Serbia, Croatia, and Bosnia and Herzegovina. A survey of quality assurance programmes of 24 computed tomography simulators in 16 facilities was conducted. A dedicated CT-to-ED phantom was scanned at 120 kV and 140 kV, to obtain CT-to-ED conversion curves as well as CTDIvol. Thoracal phantoms were scanned in the standard and extended field of view to evaluate the dosimetric effect on treatment planning and delivery. The mean age of the measured scanners was 5.5 years. The mean water HU value was –6.5 (all scanners, all voltages) and air HU value was –997. Extended field of view computed tomography data differ from the standard field of view and differences between conversion curves have significant dosimetric impact. The CTDI data showed a large range of values between centers. Better quality assurance of computed tomography simulators in all countries is recommended. The CT-to-ED curve could be used as default at one voltage and per manufacturer. Extended field of view imaging can be used, but treatment planning should be avoided in the regions out of the standard field of view.

Keywords