The accuracy of helium ion CT based particle therapy range prediction

• Verfasst von: Volz, Lennart [VerfasserIn]
• Verfasst von: Collins-Fekete, C.-A. [VerfasserIn]
• Verfasst von: Bär, E. [VerfasserIn]
• Verfasst von: Brons, Stephan [VerfasserIn]
• Verfasst von: Graeff, C. [VerfasserIn]
• Verfasst von: Johnson, R. P. [VerfasserIn]
• Verfasst von: Runz, Armin [VerfasserIn]
• Verfasst von: Sarosiek, C. [VerfasserIn]
• Verfasst von: Schulte, R. W. [VerfasserIn]
• Verfasst von: Seco, Joao [VerfasserIn]
• Titel: The accuracy of helium ion CT based particle therapy range prediction
• Titelzusatz: an experimental study comparing different particle and x-ray CT modalities
• Verf.angabe: L Volz, C-A Collins-Fekete, E Bär, S Brons, C Graeff, RP Johnson, A Runz, C Sarosiek, RW Schulte and J Seco
• E-Jahr: 2021
• Jahr: 29 November 2021
• Umfang: 17 S.
• Fussnoten: Gesehen am 27.01.2022
• Titel Quelle: Enthalten in: Physics in medicine and biology
• Ort Quelle: Bristol : IOP Publ., 1956
• Jahr Quelle: 2021
• Band/Heft Quelle: 66(2021), 23, Artikel-ID 235010, Seite 1-17
• ISSN Quelle: 1361-6560
• DOI: doi:10.1088/1361-6560/ac33ec
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1787330893

Abstract

This work provides a quantitative assessment of helium ion CT (HeCT) for particle therapy treatment planning. For the first time, HeCT based range prediction accuracy in a heterogeneous tissue phantom is presented and compared to single-energy x-ray CT (SECT), dual-energy x-ray CT (DECT) and proton CT (pCT). HeCT and pCT scans were acquired using the US pCT collaboration prototype particle CT scanner at the Heidelberg Ion-Beam Therapy Center. SECT and DECT scans were done with a Siemens Somatom Definition Flash and converted to RSP. A Catphan CTP404 module was used to study the RSP accuracy of HeCT. A custom phantom of 20 cm diameter containing several tissue equivalent plastic cubes was used to assess the spatial resolution of HeCT and compare it to DECT. A clinically realistic heterogeneous tissue phantom was constructed using cranial slices from a pig head placed inside a cylindrical phantom (ø150 mm). A proton beam (84.67 mm range) depth-dose measurement was acquired using a stack of GafchromicTM EBT-XD films in a central dosimetry insert in the phantom. CT scans of the phantom were acquired with each modality, and proton depth-dose estimates were simulated based on the reconstructions. The RSP accuracy of HeCT for the plastic phantom was found to be 0.3 ± 0.1%. The spatial resolution for HeCT of the cube phantom was 5.9 ± 0.4 lp cm−1 for central, and 7.6 ± 0.8 lp cm−1 for peripheral cubes, comparable to DECT spatial resolution (7.7 ± 0.3 lp cm−1 and 7.4 ± 0.2 lp cm−1, respectively). For the pig head, HeCT, SECT, DECT and pCT predicted range accuracy was 0.25%, −1.40%, −0.45% and 0.39%, respectively. In this study, HeCT acquired with a prototype system showed potential for particle therapy treatment planning, offering RSP accuracy, spatial resolution, and range prediction accuracy comparable to that achieved with a commercial DECT scanner. Still, technical improvements of HeCT are needed to enable clinical implementation.