ESTRO 2024 - Abstract Book

S3596

Physics - Dose prediction, optimisation and applications of photon and electron planning

ESTRO 2024

[5] Bethany Rothwell et al. “Treatment planning considerations for the development of FLASH proton therapy”. In: Radiotherapy and oncology: journal of the European Society for Therapeutic Radiology and Oncology 175 (Oct. 2022), pp. 222–230. issn: 1879-0887. doi: 10.1016/J.RADONC.2022.08.00 13

[6] J. Perl et al. “TOPAS: An innovative proton Monte Carlo platform for research and clinical applications”. In: Medical Physics 39.11 (2012), pp. 6818–6837. issn: 00942405. doi: 10.1118/1.4758060.

[7] Hans-Peter Wieser et al. “Development of the open-source dose calculation and optimization toolkit matRad”. In: Med. Phys 44.6 (2556). doi: 10.1002/mp.12251.

[8] L Whitmore et al. “Focused VHEE (very high energy electron) beams and dose delivery for radiotherapy applications”. In: Scientific Reports | 11 (2021), p. 14013. doi: 10.1038/s41598-021-93276-8.

[9] Adam H. Aitkenhead et al. “Automated Monte-Carlo re-calculation of proton therapy plans using Geant4/Gate: Implementation and comparison to plan-specific quality assurance measurements”. In: British Journal of Radiology 93.1114 (Oct. 2020). issn: 1748880X. doi: 10.1259/BJR.20200228/FORMAT/EPUB.13

[10] Jean Bourhis et al. “Clinical translation of FLASH radiotherapy: Why and how?” In: Radiotherapy and Oncology 139 (Oct. 2019), pp. 11–17. issn: 0167-8140. doi: 10.1016/J.RADONC.2019.04.008. 13

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Digital Poster

Validation of CBCT SABR planning - A roadmap with KV-CBCT calibration curves for the Monaco system

Arun Jaganathan, Dominika Oborska-Kumaszynska, Julian Liu, Edis Dedovic, Oi-Ching Choi

Nuffield Health Cancer Centre London, Physics, London, United Kingdom

Purpose/Objective:

This study aims to evaluate the re-planning dose calculation accuracy by comparing the Stereotactic ablative radiotherapy (SABR) lung plans generated on CT, CBCT, and synthetic overwritten CBCT images of the CIRS DYNAMIC THORAX PHANTOM MODEL 008A by applying different calibration curves. This will contribute to the improvement of the accuracy and reliability of radiation therapy treatments, specifically adaptive planning [1].

Material/Methods:

Calibration curves were generated by scanning a CIRS phantom and an RMI Tissue Characterization Phantom using CBCT with Elekta XVI 5.0.6. These curves map Hounsfield Unit (HU) values to Relative Electron Density (RED). RED is used for accurate dose calculations in radiation therapy. A CT image generated on the Siemens Somatom Open CT simulator was used as the reference and it was considered as the gold standard for comparison during the calibration process. The Elekta XVI system underwent full calibration and optimization to ensure accurate measurements and images [2,3,4]. A site-specific approach was developed to calibrate the fan-beam CBCT HU for treatment planning using CIRS ELECTRON DENSITY PHANTOM MODEL 062M and Gammex 467 Tissue Characterisation Phantom. For