Initial clinical evaluation of PET-based ion beam therapy monitoring under consideration of organ motion
Purpose: Intrafractional organ motion imposes considerable challenges to scanned ion beam therapy and demands for a thorough verification of the applied treatment. At the Heidelberg Ion-Beam Therapy Center (HIT), the scanned ion beam delivery is verified by means of postirradiation positron-emission...
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| Main Authors: | , , , , , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
28 January 2016
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| In: |
Medical physics
Year: 2016, Volume: 43, Issue: 2, Pages: 975-982 |
| ISSN: | 2473-4209 |
| DOI: | 10.1118/1.4940356 |
| Online Access: | Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1118/1.4940356 Verlag, lizenzpflichtig, Volltext: https://aapm.onlinelibrary.wiley.com/doi/abs/10.1118/1.4940356 
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| Author Notes: | Christopher Kurz, Julia Bauer, Daniel Unholtz, Daniel Richter, Klaus Herfarth, Jürgen Debus, Katia Parodi |
| Summary: | Purpose: Intrafractional organ motion imposes considerable challenges to scanned ion beam therapy and demands for a thorough verification of the applied treatment. At the Heidelberg Ion-Beam Therapy Center (HIT), the scanned ion beam delivery is verified by means of postirradiation positron-emission-tomography (PET) imaging. This work presents a first clinical evaluation of PET-based treatment monitoring in ion beam therapy under consideration of target motion. Methods: Three patients with mobile liver lesions underwent scanned carbon ion irradiation at HIT and postirradiation PET/CT (x-ray-computed-tomography) imaging with a commercial scanner. Respiratory motion was recorded during irradiation and subsequent image acquisition. This enabled a time-resolved (4D) calculation of the expected irradiation-induced activity pattern and, for one patient where an additional 4D CT was acquired at the PET/CT scanner after treatment, a motion-compensated PET image reconstruction. For the other patients, PET data were reconstructed statically. To verify the treatment, calculated prediction and reconstructed measurement were compared with a focus on the ion beam range. Results: Results in the current three patients suggest that for motion amplitudes in the order of 2 mm there is no benefit from incorporating respiratory motion information into PET-based treatment monitoring. For a target motion in the order of 10 mm, motion-related effects become more severe and a time-resolved modeling of the expected activity distribution can lead to an improved data interpretation if a sufficient number of true coincidences is detected. Benefits from motion-compensated PET image reconstruction could not be shown conclusively at the current stage. Conclusions: The feasibility of clinical PET-based treatment verification under consideration of organ motion has been shown for the first time. Improvements in noise-robust 4D PET image reconstruction are deemed necessary to enhance the clinical potential. |
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| Item Description: | Gesehen am 04.06.2020 |
| Physical Description: | Online Resource |
| ISSN: | 2473-4209 |
| DOI: | 10.1118/1.4940356 |