دورية أكاديمية
Planning target volume margin assessment for online adaptive MR-guided dose-escalation in rectal cancer on a 1.5 T MR-Linac.
| العنوان: | Planning target volume margin assessment for online adaptive MR-guided dose-escalation in rectal cancer on a 1.5 T MR-Linac. |
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| المؤلفون: | Eijkelenkamp H; Department of Radiation Oncology, University Medical Center Utrecht, The Netherlands. Electronic address: H.Eijkelenkamp-2@umcutrecht.nl., Boekhoff MR; Department of Radiation Oncology, University Medical Center Utrecht, The Netherlands., Verweij ME; Department of Radiation Oncology, University Medical Center Utrecht, The Netherlands., Peters FP; Department of Radiation Oncology, Leiden University Medical Center, The Netherlands; Department of Radiation Oncology, Netherlands Cancer Institute/Antoni van Leeuwenhoek, The Netherlands., Meijer GJ; Department of Radiation Oncology, University Medical Center Utrecht, The Netherlands., Intven MPW; Department of Radiation Oncology, University Medical Center Utrecht, The Netherlands. |
| المصدر: | Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology [Radiother Oncol] 2021 Sep; Vol. 162, pp. 150-155. Date of Electronic Publication: 2021 Jul 17. |
| نوع المنشور: | Clinical Trial; Journal Article |
| اللغة: | English |
| بيانات الدورية: | Publisher: Elsevier Scientific Publishers Country of Publication: Ireland NLM ID: 8407192 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1879-0887 (Electronic) Linking ISSN: 01678140 NLM ISO Abbreviation: Radiother Oncol Subsets: MEDLINE |
| أسماء مطبوعة: | Publication: Limerick : Elsevier Scientific Publishers Original Publication: Amsterdam : Elsevier Science Publishers, c1983- |
| مواضيع طبية MeSH: | Radiotherapy Planning, Computer-Assisted* , Rectal Neoplasms*/diagnostic imaging , Rectal Neoplasms*/radiotherapy, Humans ; Magnetic Resonance Imaging ; Motion ; Particle Accelerators |
| مستخلص: | Purpose: This study assessed the margins needed to cover tumor intrafraction motion during an MR-guided radiotherapy (MRgRT) dose-escalation strategy in intermediate risk rectal cancer. Methods: Fifteen patients with rectal cancer were treated with neoadjuvant short-course radiotherapy, 5x5 Gy, according to an online adaptive workflow on a 1.5 T MR-linac. Per patient, 26 3D T2 weighted MRIs were made; one reference scan preceding treatment and five scans per treatment fraction. The primary tumor was delineated on each scan as gross tumor volume (GTV). Target coverage margins were assessed by isotropically expanding the reference GTV until more than 95% of the voxels of the sequential GTVs were covered. A margin with a coverage probability threshold of 90% was defined as adequate. Intra- and interfraction margins to cope with the movement of the GTV in the period between scans were calculated to indicate the target volume margins. Furthermore, the margin needed to cover GTV movement was calculated for different time intervals. Results: The required margins to cover inter- and intrafraction GTV motion were 17 mm and 6 mm, respectively. Analysis based on time intervals between scans showed smaller margins were needed for adequate GTV coverage as time intervals became shorter, with a 4 mm margin required for a procedure of 15 min or less. Conclusion: The shorter the treatment time, the smaller the margins needed to cover for the GTV movement during an online adaptive MRgRT dose-escalation strategy for intermediate risk rectal cancer. When time intervals between replanning and the end of dose delivery could be reduced to 15 min, a 4 mm margin would allow adequate target coverage. Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.) |
| فهرسة مساهمة: | Keywords: Dose-escalation; Intrafraction motion; MR guided radiation therapy; Margin assessment; Online adaptive radiotherapy; Rectal cancer |
| تواريخ الأحداث: | Date Created: 20210719 Date Completed: 20211101 Latest Revision: 20220531 |
| رمز التحديث: | 20221213 |
| DOI: | 10.1016/j.radonc.2021.07.011 |
| PMID: | 34280404 |
| قاعدة البيانات: | MEDLINE |
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