MRI-based inter- and intrafraction motion analysis of the pancreatic tail and spleen as preparation for adaptive MRI-guided radiotherapy in neuroblastoma.

Autor: Van Ommen F; Department of Radiation Oncology, University Medical Center Utrecht, Heidelberglaan 100, Utrecht, 3584 CX, The Netherlands. f.vanommen@umcutrecht.nl., le Quellenec GAT; Department of Radiation Oncology, University Medical Center Utrecht, Heidelberglaan 100, Utrecht, 3584 CX, The Netherlands.; Department of Radiation Oncology, Institut de Cancérologie de l'Ouest, Nantes, France., Willemsen-Bosman ME; Department of Radiation Oncology, University Medical Center Utrecht, Heidelberglaan 100, Utrecht, 3584 CX, The Netherlands., van Noesel MM; Department of Radiation Oncology, University Medical Center Utrecht, Heidelberglaan 100, Utrecht, 3584 CX, The Netherlands.; Princess Máxima Center for Pediatric Oncology, Utrecht, The Netherlands., van den Heuvel-Eibrink MM; Princess Máxima Center for Pediatric Oncology, Utrecht, The Netherlands., Seravalli E; Department of Radiation Oncology, University Medical Center Utrecht, Heidelberglaan 100, Utrecht, 3584 CX, The Netherlands., Kroon PS; Department of Radiation Oncology, University Medical Center Utrecht, Heidelberglaan 100, Utrecht, 3584 CX, The Netherlands., Janssens GO; Department of Radiation Oncology, University Medical Center Utrecht, Heidelberglaan 100, Utrecht, 3584 CX, The Netherlands.; Princess Máxima Center for Pediatric Oncology, Utrecht, The Netherlands.
Jazyk: angličtina
Zdroj: Radiation oncology (London, England) [Radiat Oncol] 2023 Oct 02; Vol. 18 (1), pp. 160. Date of Electronic Publication: 2023 Oct 02.
DOI: 10.1186/s13014-023-02347-9
Abstrakt: Background: In pediatric radiotherapy treatment planning of abdominal tumors, dose constraints to the pancreatic tail/spleen are applied to reduce late toxicity. In this study, an analysis of inter- and intrafraction motion of the pancreatic tail/spleen is performed to estimate the potential benefits of online MRI-guided radiotherapy (MRgRT).
Materials and Methods: Ten randomly selected neuroblastoma patients (median age: 3.4 years), irradiated with intensity-modulated arc therapy at our department (prescription dose: 21.6/1.8 Gy), were retrospectively evaluated for inter- and intrafraction motion of the pancreatic tail/spleen. Three follow-up MRIs (T2- and T1-weighted ± gadolinium) were rigidly registered to a planning CT (pCT), on the vertebrae around the target volume. The pancreatic tail/spleen were delineated on all MRIs and pCT. Interfraction motion was defined as a center of gravity change between pCT and T2-weighted images in left-right (LR), anterior-posterior (AP) and cranial-caudal (CC) direction. For intrafraction motion analysis, organ position on T1-weighted ± gadolinium was compared to T2-weighted. The clinical radiation plan was used to estimate the dose received by the pancreatic tail/spleen for each position.
Results: The median (IQR) interfraction motion was minimal in LR/AP, and largest in CC direction; pancreatic tail 2.5 mm (8.9), and spleen 0.9 mm (3.9). Intrafraction motion was smaller, but showed a similar motion pattern (pancreatic tail, CC: 0.4 mm (1.6); spleen, CC: 0.9 mm (2.8)). The differences of Dmean associated with inter- and intrafraction motions ranged from - 3.5 to 5.8 Gy for the pancreatic tail and - 1.2 to 3.0 Gy for the spleen. In 6 out of 10 patients, movements of the pancreatic tail and spleen were highlighted as potentially clinically significant because of ≥ 1 Gy dose constraint violation.
Conclusion: Inter- and intrafraction organ motion results into unexpected constrain violations in 60% of a randomly selected neuroblastoma cohort, supporting further prospective exploration of MRgRT.
(© 2023. BioMed Central Ltd., part of Springer Nature.)
Databáze: MEDLINE
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