Repeated deep-inspiration breath-hold CT scans at planning underestimate the actual motion between breath-holds at treatment for lung cancer and lymphoma patients.

Autor: Hoffmann L; Department of Oncology, Aarhus University Hospital, Aarhus, Denmark; Department of Clinical Medicine, Aarhus University, Aarhus, Denmark. Electronic address: Lone.Hoffmann@aarhus.rm.dk., Ehmsen ML; Danish Center for Proton Therapy, Aarhus University Hospital, Aarhus, Denmark., Hansen J; Department of Oncology, Aarhus University Hospital, Aarhus, Denmark., Hansen R; Department of Oncology, Aarhus University Hospital, Aarhus, Denmark., Knap MM; Department of Oncology, Aarhus University Hospital, Aarhus, Denmark., Mortensen HR; Danish Center for Proton Therapy, Aarhus University Hospital, Aarhus, Denmark., Poulsen PR; Department of Clinical Medicine, Aarhus University, Aarhus, Denmark; Danish Center for Proton Therapy, Aarhus University Hospital, Aarhus, Denmark., Ravkilde T; Department of Oncology, Aarhus University Hospital, Aarhus, Denmark., Rose HK; Department of Oncology, Aarhus University Hospital, Aarhus, Denmark., Schmidt HH; Department of Oncology, Aarhus University Hospital, Aarhus, Denmark., Worm ES; Department of Oncology, Aarhus University Hospital, Aarhus, Denmark., Møller DS; Department of Oncology, Aarhus University Hospital, Aarhus, Denmark; Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.
Jazyk: angličtina
Zdroj: Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology [Radiother Oncol] 2023 Nov; Vol. 188, pp. 109887. Date of Electronic Publication: 2023 Sep 01.
DOI: 10.1016/j.radonc.2023.109887
Abstrakt: Purpose/objective: Deep-inspiration breath-hold (DIBH) during radiotherapy may reduce dose to the lungs and heart compared to treatment in free breathing. However, intra-fractional target shifts between several breath-holds may decrease target coverage. We compared target shifts between four DIBHs at the planning-CT session with those measured on CBCT-scans obtained pre- and post-DIBH treatments.
Material/methods: Twenty-nine lung cancer and nine lymphoma patients were treated in DIBH. An external gating block was used as surrogate for the DIBH-level with a window of 2 mm. Four DIBH CT-scans were acquired: one for planning (CT DIBH3 ) and three additional (CT DIBH1,2,4 ) to assess the intra-DIBH target shifts at scanning by registration to CT DIBH3 . During treatment, pre-treatment (CBCT pre ) and post-treatment (CBCT post ) scans were acquired. For each pair of CBCT pre/post , the target intra-DIBH shift was determined. For lung cancer, tumour (GTV-T lung ) and lymph nodes (GTV-N lung ) were analysed separately. Group mean (GM), systematic and random errors, and GM for the absolute maximum shifts (GM max ) were calculated for the shifts between CT DIBH1,2,3,4 and between CBCT pre/post .
Results: For GTV-T lung , GM max was larger at CBCT than CT in all directions. GM max in cranio-caudal direction was 3.3 mm (CT)and 6.1 mm (CBCT). The standard deviations of the shifts in the left-right and cranio-caudal directions were larger at CBCT than CT. For GTV-N lung and CTV lymphoma , no difference was found in GM max or SD.
Conclusion: Intra-DIBH shifts at planning-CT session are generally smaller than intra-DIBH shifts observed at CBCT pre/post and therefore underestimate the intra-fractional DIBH uncertainty during treatment. Lung tumours show larger intra-fractional variations than lymph nodes and lymphoma targets.
Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2023 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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