Clinical workflow of cone beam computer tomography-based daily online adaptive radiotherapy with offline magnetic resonance guidance: the Modular Adaptive Radiotherapy System (MARS)
Purpose: The Ethos (Varian Medical Systems) radiotherapy device combines semi-automated anatomy detection and plan generation for cone beam computer tomography (CBCT)-based daily online adaptive radiotherapy (oART). However, CBCT offers less soft tissue contrast than magnetic resonance imaging (MRI)...
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| Main Authors: | , , , , , , , , , , , , , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
19 March 2024
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| In: |
Cancers
Year: 2024, Volume: 16, Issue: 6, Pages: 1-14 |
| ISSN: | 2072-6694 |
| DOI: | 10.3390/cancers16061210 |
| Online Access: | Verlag, kostenfrei, Volltext: https://doi.org/10.3390/cancers16061210 Verlag, kostenfrei, Volltext: https://www.mdpi.com/2072-6694/16/6/1210 
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| Author Notes: | Ji-Young Kim, Bouchra Tawk, Maximilian Knoll, Philipp Hoegen-Saßmannshausen, Jakob Liermann, Peter E. Huber, Mona Lifferth, Clemens Lang, Peter Häring, Regula Gnirs, Oliver Jäkel, Heinz-Peter Schlemmer, Jürgen Debus, Juliane Hörner-Rieber and Fabian Weykamp |
| Summary: | Purpose: The Ethos (Varian Medical Systems) radiotherapy device combines semi-automated anatomy detection and plan generation for cone beam computer tomography (CBCT)-based daily online adaptive radiotherapy (oART). However, CBCT offers less soft tissue contrast than magnetic resonance imaging (MRI). This work aims to present the clinical workflow of CBCT-based oART with shuttle-based offline MR guidance. Methods: From February to November 2023, 31 patients underwent radiotherapy on the Ethos (Varian, Palo Alto, CA, USA) system with machine learning (ML)-supported daily oART. Moreover, patients received weekly MRI in treatment position, which was utilized for daily plan adaptation, via a shuttle-based system. Initial and adapted treatment plans were generated using the Ethos treatment planning system. Patient clinical data, fractional session times (MRI + shuttle transport + positioning, adaptation, QA, RT delivery) and plan selection were assessed for all fractions in all patients. Results: In total, 737 oART fractions were applied and 118 MRIs for offline MR guidance were acquired. Primary sites of tumors were prostate (n = 16), lung (n = 7), cervix (n = 5), bladder (n = 1) and endometrium (n = 2). The treatment was completed in all patients. The median MRI acquisition time including shuttle transport and positioning to initiation of the Ethos adaptive session was 53.6 min (IQR 46.5-63.4). The median total treatment time without MRI was 30.7 min (IQR 24.7-39.2). Separately, median adaptation, plan QA and RT times were 24.3 min (IQR 18.6-32.2), 0.4 min (IQR 0.3-1,0) and 5.3 min (IQR 4.5-6.7), respectively. The adapted plan was chosen over the scheduled plan in 97.7% of cases. Conclusion: This study describes the first workflow to date of a CBCT-based oART combined with a shuttle-based offline approach for MR guidance. The oART duration times reported resemble the range shown by previous publications for first clinical experiences with the Ethos system. |
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| Item Description: | Gesehen am 16.08.2024 |
| Physical Description: | Online Resource |
| ISSN: | 2072-6694 |
| DOI: | 10.3390/cancers16061210 |