Dosimetric effects of intrafractional isocenter variation during deep inspiration breath-hold for breast cancer patients using surface-guided radiotherapy

Forskningsoutput: TidskriftsbidragArtikel i vetenskaplig tidskrift

Abstract

The aim of this study was to investigate potential dose reductions to the heart, left anterior descending coronary artery (LAD), and ipsilateral lung for left-sided breast cancer using visually guided deep inspiration breath-hold (DIBH) with the optical surface scanning system Catalyst™, and how these potential dosimetric benefits are affected by intrafractional motion in between breath holds. For both DIBH and free breathing (FB), treatment plans were created for 20 tangential and 20 locoregional left-sided breast cancer patients. During DIBH treatment, beam-on was triggered by a region of interest on the xiphoid process using a 3 mm gating window. Using a novel nonrigid algorithm, the Catalyst™ system allows for simultaneous real-time tracking of the isocenter position, which was used to calculate the intrafractional DIBH isocenter reproducibility. The 50% and 90% cumulative probabilities and maximum values of the intrafractional DIBH isocenter reproducibility were calculated and to obtain the dosimetric effect isocenter shifts corresponding to these values were performed in the treatment planning system. For both tangential and locoregional treatment, the dose to the heart, LAD and ipsilateral lung was significantly reduced for DIBH compared to FB. The intrafractional DIBH isocenter reproducibility was very good for the majority of the treatment sessions, with median values of approximately 1 mm in all three translational directions. However, for a few treatment sessions, intrafractional DIBH isocenter reproducibility of up to 5 mm was observed, which resulted in large dosimetric effects on the target volume and organs at risk. Hence, it is of importance to set tolerance levels on the intrafractional isocenter motion and not only perform DIBH based on the xiphoid process.

Detaljer

Författare
Enheter & grupper
Externa organisationer
  • Skåne University Hospital
Forskningsområden

Ämnesklassifikation (UKÄ) – OBLIGATORISK

  • Radiologi och bildbehandling

Nyckelord

Originalspråkengelska
Sidor (från-till)25-38
TidskriftJournal of Applied Clinical Medical Physics
Volym19
Utgåva nummer1
Tidigt onlinedatum2017 nov 15
StatusPublished - 2018 jan
PublikationskategoriForskning
Peer review utfördJa

Relaterad forskningsoutput

Anneli Edvardsson, 2018 sep, Lund: Lund University, Faculty of Science, Department of Medical Radiation Physics. 170 s.

Forskningsoutput: AvhandlingDoktorsavhandling (sammanläggning)

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