Dose calculation accuracy of a new high-performance ring-gantry CBCT imaging system for prostate and lung cancer patients.

Autor: Sijtsema ND; Department of Radiotherapy, Erasmus MC Cancer Institute, University Medical Center Rotterdam, Rotterdam, The Netherlands. Electronic address: n.sijtsema@erasmusmc.nl., Penninkhof JJ; Department of Radiotherapy, Erasmus MC Cancer Institute, University Medical Center Rotterdam, Rotterdam, The Netherlands., van de Schoot AJAJ; Department of Radiotherapy, Erasmus MC Cancer Institute, University Medical Center Rotterdam, Rotterdam, The Netherlands., Kunnen B; Department of Radiotherapy, Erasmus MC Cancer Institute, University Medical Center Rotterdam, Rotterdam, The Netherlands., Sluijter JH; Department of Radiotherapy, Erasmus MC Cancer Institute, University Medical Center Rotterdam, Rotterdam, The Netherlands., van de Pol M; Department of Radiotherapy, Erasmus MC Cancer Institute, University Medical Center Rotterdam, Rotterdam, The Netherlands., Froklage FE; Department of Radiotherapy, Erasmus MC Cancer Institute, University Medical Center Rotterdam, Rotterdam, The Netherlands., Dirkx MLP; Department of Radiotherapy, Erasmus MC Cancer Institute, University Medical Center Rotterdam, Rotterdam, The Netherlands., Petit SF; Department of Radiotherapy, Erasmus MC Cancer Institute, University Medical Center Rotterdam, Rotterdam, The Netherlands.
Jazyk: angličtina
Zdroj: Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology [Radiother Oncol] 2024 Oct 24; Vol. 202, pp. 110596. Date of Electronic Publication: 2024 Oct 24.
DOI: 10.1016/j.radonc.2024.110596
Abstrakt: Background and Purpose: The recently introduced high-performance CBCT imaging system called HyperSight offers improved Hounsfield units (HU) accuracy, a larger CBCT field-of-view and improved image quality compared to conventional ring gantry CBCT, possibly enabling treatment planning on CBCT imaging directly. In this study, we evaluated whether the dose calculation accuracy on HyperSight CBCT was sufficient for treatment planning in prostate and lung cancer patients.
Materials and Methods: HyperSight CBCT was compared to planning CT (pCT) in terms of HU-to-mass density (MD) calibration curves. For twenty prostate patients and twenty lung patients, differences in DVH parameters, and 3D global gamma between dose distributions calculated on pCT and free breathing HyperSight CBCT were evaluated. For this purpose, HyperSight CBCT acquired at the first fraction was rigidly registered to the pCT, delineations from the CT were propagated and the dose was recalculated on the HyperSight CBCT.
Results: For each insert of the HU-to-MD calibration phantom, the HU values of HyperSight CBCT and pCT agreed within 35 HU. For prostate maximum deviations in PTV D mean , V 95% and V 107% were 1.8 %, -1.1 % and < 0.1 % respectively. For lung PTV V 95% was generally lower (median -1.1 %) and PTV V 107% was generally higher (median 1.1 %) on HyperSight CBCT due to breathing motion artifacts. The average (±SD) 2 %/2mm gamma pass rate was 98.7 %±1.2 % for prostate cancer patients and 96.2 %±2.1 % for lung cancer patients.
Conclusion: HyperSight CBCT enabled accurate dose calculation for prostate cancer patients, without implementation of a specific HyperSight CBCT-to-MD curve. For lung cancer patients, breathing motion hampered accurate dose calculations.
Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Erasmus MC Cancer Institute has research collaborations with Varian, a Siemens Healthineers Company (Palo Alto, CA, USA), Elekta AB (Stockholm, Sweden) and Accuray (Sunnyvale, CA, USA). Varian was not involved in this study and had no role in study design, data collection and analysis, and decisions on preparation of the manuscript.
(Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
Externí odkaz: