Ultrafast single breath-hold cone-beam CT lung cancer imaging with faster linac gantry rotation
Purpose - Lung tumors treated with hypo-fractionated deep-inspiration breath-hold stereotactic body radiotherapy benefit from fast imaging and treatment. Single breath-hold cone-beam-CT (CBCT) could reduce motion artifacts and improve treatment precision. Thus, gantry speed was accelerated to 18°/s,...
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| Main Authors: | , , , , , , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
June 2019
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| In: |
Radiotherapy and oncology
Year: 2019, Volume: 135, Pages: 78-85 |
| ISSN: | 1879-0887 |
| DOI: | 10.1016/j.radonc.2019.02.004 |
| Online Access: | Verlag, Volltext: https://doi.org/10.1016/j.radonc.2019.02.004 Verlag: http://www.sciencedirect.com/science/article/pii/S0167814019300702 
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| Author Notes: | Anna Arns, Hansjoerg Wertz, Judit Boda-Heggemann, Frank Schneider, Manuel Blessing, Yasser Abo-Madyan, Volker Steil, Frederik Wenz, Jens Fleckenstein |
| Summary: | Purpose - Lung tumors treated with hypo-fractionated deep-inspiration breath-hold stereotactic body radiotherapy benefit from fast imaging and treatment. Single breath-hold cone-beam-CT (CBCT) could reduce motion artifacts and improve treatment precision. Thus, gantry speed was accelerated to 18°/s, limiting acquisition time to 10-20s. Image quality, dosimetry and registration accuracy were compared with standard-CBCT (3°/s). - Methods and materials - For proof-of-concept, image quality was analyzed following customer acceptance tests, CT-dose index measured, and registration accuracy determined with an off-centered ball-bearing-phantom. A lung-tumor patient was simulated with differently shaped tumor-mimicking inlays in a thorax-phantom. Signal-to-noise-ratio, contrast-to-noise-ratio and geometry of the inlays quantified image quality. Dose was measured in representative positions. Registration accuracy was determined with inlays scanned in pre-defined positions. Manual, automatic (clinical software) and objective-automatic (in-house-developed) registration was performed on planning-CT, offsets between results and applied shifts were compared. - Results - Image quality of ultrafast-CBCT was adequate for high-contrast areas, despite contrast-reduction of ∼80% due to undersampling. Dose-output was considerably reduced by 60-83% in presented setup; variations are due to gantry-braking characteristics. Registration accuracy was maintained better than 1mm, mean displacement errors were 0.0±0.2mm with objective-automatic registration. Ultrafast-CBCT showed no significant registration differences to standard-CBCT. - Conclusions - This study of first tests with faster gantry rotation of 18°/s showed promising results for ultrafast high-contrast lung tumor CBCT imaging within single breath-hold of 10-20s. Such fast imaging times, in combination with fast treatment delivery, could pave the way for intra-fractional combined imaging and treatment within one breath-hold phase, and thus mitigate residual motion and increase treatment accuracy and patient comfort. Even generally speaking, faster gantry rotation could set a benchmark with immense clinical impact where time matters most: palliative patient care, general reduction in uncertainty, and increase in patient throughput especially important for emerging markets with high patient numbers. |
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| Item Description: | Gesehen am 18.11.2019 Available online 16 March 2019 |
| Physical Description: | Online Resource |
| ISSN: | 1879-0887 |
| DOI: | 10.1016/j.radonc.2019.02.004 |