CyberKnife Xsight versus fiducial-based target-tracking: a novel 3D dosimetric comparison in a dynamic phantom.

Autor: Klein TJ; School of Physics, Mathematics and Computing, The University of Western Australia, 35 Stirling Highway, Mailbag M013, Crawley, WA, 6009, Australia., Gill S; School of Physics, Mathematics and Computing, The University of Western Australia, 35 Stirling Highway, Mailbag M013, Crawley, WA, 6009, Australia.; Department of Radiation Oncology, Sir Charles Gairdner Hospital, Nedlands, WA, Australia., Ebert MA; School of Physics, Mathematics and Computing, The University of Western Australia, 35 Stirling Highway, Mailbag M013, Crawley, WA, 6009, Australia.; Department of Radiation Oncology, Sir Charles Gairdner Hospital, Nedlands, WA, Australia., Grogan G; Department of Radiation Oncology, Sir Charles Gairdner Hospital, Nedlands, WA, Australia.; Radiotherapy Physics Department, Churchill Hospital, Old Road, Headington, Oxford, UK., Smith W; School of Physics, Mathematics and Computing, The University of Western Australia, 35 Stirling Highway, Mailbag M013, Crawley, WA, 6009, Australia.; Department of Radiation Oncology, Sir Charles Gairdner Hospital, Nedlands, WA, Australia., Alkhatib Z; Department of Radiation Oncology, Sir Charles Gairdner Hospital, Nedlands, WA, Australia., Geraghty J; Department of Radiation Oncology, Sir Charles Gairdner Hospital, Nedlands, WA, Australia., Scott AJD; Department of Radiation Oncology, Sir Charles Gairdner Hospital, Nedlands, WA, Australia., Brown A; Department of Radiation Oncology, Sir Charles Gairdner Hospital, Nedlands, WA, Australia., Rowshanfarzad P; School of Physics, Mathematics and Computing, The University of Western Australia, 35 Stirling Highway, Mailbag M013, Crawley, WA, 6009, Australia. pejman.rowshanfarzad@uwa.edu.au.
Jazyk: angličtina
Zdroj: Radiation oncology (London, England) [Radiat Oncol] 2022 Sep 08; Vol. 17 (1), pp. 154. Date of Electronic Publication: 2022 Sep 08.
DOI: 10.1186/s13014-022-02123-1
Abstrakt: Background: The CyberKnife Xsight lung-tracking system (XLTS) provides an alternative to fiducial-based target-tracking systems (FTTS) for non-small-cell lung cancer (NSCLC) patients without invasive fiducial insertion procedures. This study provides a method for 3D independent dosimetric verification of the accuracy of the FTTS compared to the XLTS without relying on log-files generated by the CyberKnife system.
Methods: A respiratory motion trace was taken from a 4D-CT of a real lung cancer patient and applied to a modified QUASAR™ respiratory motion phantom. A novel approach to 3D dosimetry was developed using Gafchromic EBT3 film, allowing the 3D dose distribution delivered to the moving phantom to be reconstructed. Treatments were planned using the recommended margins for one and three fiducial markers and XLTS 2-view, 1-view and 0-view target-tracking modalities. The dose delivery accuracy was analysed by comparing the reconstructed dose distributions to the planned dose distributions using gamma index analysis.
Results: For the 3%/2 mm gamma criterion, gamma passing rates up to 99.37% were observed for the static deliveries. The 3-fiducial and 1-fiducial-based deliveries exhibited passing rates of 93.74% and 97.82%, respectively, in the absence of target rotation. When target rotation was considered, the passing rate for 1-fiducial tracking degraded to 91.24%. The passing rates observed for XLTS 2-view, 1-view and 0-view target-tracking were 92.78%, 96.22% and 76.08%, respectively.
Conclusions: Except for the XLTS 0-view, the dosimetric accuracy of the XLTS was comparable to the FTTS under equivalent treatment conditions. This study gives us further confidence in the CyberKnife XLTS and FTTS systems.
(© 2022. The Author(s).)
Databáze: MEDLINE
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