Investigating the spatial accuracy of CBCT-guided cranial radiosurgery: A phantom end-to-end test study

Calvo-Ortega, J.F.; Hermida-López, M.; Moragues-Femenía, S.; Pozo-Massó, M.; Casals-Farran, J.

doi:10.1016/j.ejmp.2017.02.020

Cited by 4 publications

(2 citation statements)

References 24 publications

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“…When looking at non-continuous volumetric imaging alone (i.e., CBCT), there are a number of reports of endto-end tests exceeding the limits of 1 mm [3,[198][199][200][201], even though the recent COMP report on CBCT advised achieving a geometric accuracy of <1 mm [201]. Hence, the accuracy of CBCT alone may not necessarily be sufficient for SRS, especially when further considering patient motion during treatment (see the "Patient positioning and target volume localization" and "Motion management" sections above).…”

Section: However For Fsrt and Sbrt Close To Radiation-sensitive Critmentioning

confidence: 99%

Technological quality requirements for stereotactic radiotherapy

et al. 2020

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This review details and discusses the technological quality requirements to ensure the desired quality for stereotactic radiotherapy using photon external beam radiotherapy as defined by the DEGRO Working Group Radiosurgery and Stereotactic Radiotherapy and the DGMP Working Group for Physics and Technology in Stereotactic Radiotherapy. The covered aspects of this review are 1) imaging for target volume definition, 2) patient positioning and target volume localization, 3) motion management, 4) collimation of the irradiation and beam directions, 5) dose calculation, 6) treatment unit accuracy, and 7) dedicated quality assurance measures. For each part, an expert review for current state-of-the-art techniques and their particular technological quality requirement to reach the necessary accuracy for stereotactic radiotherapy divided into intracranial stereotactic radiosurgery in one single fraction (SRS), intracranial fractionated stereotactic radiotherapy (FSRT), and extracranial stereotactic body radiotherapy (SBRT) is presented. All recommendations and suggestions for all mentioned aspects of stereotactic radiotherapy are formulated and related uncertainties and potential sources of error discussed. Additionally, further research and development needs in terms of insufficient data and unsolved problems for stereotactic radiotherapy are identified, which will serve as The authors D. Schmitt and O. Blanck contributed equally to the manuscript.

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Section: However For Fsrt and Sbrt Close To Radiation-sensitive Critmentioning

confidence: 99%

Technological quality requirements for stereotactic radiotherapy

et al. 2020

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“…End-to-end gamma (γ) index analysis (Dieterich et al 2011, Calvo-Ortega et al 2017 is commonly used to ensure acceptable level of dose delivery accuracy in SRS. Although γ index analysis considers individual patient plan, it only provides a single metrics combining the distance to agreement (DTA) and dose difference (ΔD) to quantify the agreement between the planned and the measured dose distributions.…”

Section: Introductionmentioning

confidence: 99%

Linking dose delivery accuracy and planning target margin in radiosurgery based on dose-volume histograms derived from measurement-guided dose reconstruction

et al. 2019

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In radiosurgery (SRS), the geometric uncertainties of machine-related delivery including image-guidance and hence the planning target volume (PTV) are often evaluated by the end-to-end gamma (γ) comparison that carries no information about the clinical relevance of deviations of individual SRS plans during delivery quality assurance (DQA). A proof-of-concept method was proposed to derive the PTV against both the plan- and the machine-specific delivery errors directly from the clinically relevant dose-volume histograms (DVHs) using measured-guided dose reconstruction (MGDR) during DQA. A liquid-filled detector array and a rotating phantom were used to measure sixteen arc-based radiosurgery treatments with 1 and 2 mm gross tumor volume (GTV)-to-PTV margins, producing MGDR-3D dose distribution on both the phantom and the patient CT for γ index and clinical DVH evaluations, respectively. The PTV was considered optimal when the MGDR showed the desired prescription dose coverage (V pres ) of the GTV (100% in this study). Associations of the binary V pres outcomes (<or =100%) of the GTV with the acceptance level of percent γ pass rate (γPR%) at 90 versus 95% were assessed. Further receiver operator characteristic (ROC) analysis was performed to assess the distance-to-agreement (DTA) and local dose difference (ΔD) criteria that may be suitable for treatment acceptance. From the MGDR, 100% GTV V pres was achieved in 68.8% and 100% of plans with 1 and 2 mm PTV, respectively. V pres outcomes were neither associated with γPR% at 1–2 mm DTA and 1%–3% ΔD nor the acceptance level for MGDR in the patient CT. ROC analysis shows statistically significant AUC values from 0.78–0.84 and 0.79–0.80 for MGDR phantom and patient doses, respectively. DQA by MGDR-DVH objectives offers the unique opportunity of direct assessment of the dose delivery accuracy and hence the optimal PTV without subject to the statistical correlation between γPR% and clinical metrics. Based on multi-criteria DVH objectives, clinical decision can be instantly made to adjust the treatment plan prescription.

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