Pelvic lymph node motion during cone-beam computed tomography guided stereotactic radiotherapy.

Autor:	Janssen J; Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands., Staal FHE; Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands., Langendijk JA; Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands., Both S; Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands., Brouwer CL; Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands., Aluwini S; Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands.
Jazyk:	angličtina
Zdroj:	Clinical and translational radiation oncology [Clin Transl Radiat Oncol] 2024 May 11; Vol. 47, pp. 100794. Date of Electronic Publication: 2024 May 11 (Print Publication: 2024).
DOI:	10.1016/j.ctro.2024.100794
Abstrakt:	Background and Purpose: Stereotactic body radiotherapy (SBRT) is increasingly applied for pelvic lymph node recurrence. Thus far, knowledge on pelvic lymph node motion during CBCT-guided SBRT is lacking and the applied margins vary between institutions. This study evaluated pelvic lymph node motion during CBCT-guided SBRT and assessed the currently applied PTV margins of 3 and 5 mm. Material and Methods: In total, 45 pelvic lymph node metastases were included. One observer delineated 45 GTVs on planning CT, 224 GTVs on pre-fraction and 216 on post-fraction CBCT. The GTV centroid coordinates were derived from all images for inter- and intrafraction motion analysis. Additionally, we assessed the influence of treatment time and lesion location on lesion motion. The expected coverage of a 3-mm and 5-mm PTV margin was assessed using the inclusiveness index for GTVs on pre- and post-fraction CBCT. Results: Lymph node interfraction motion was limited to 5 mm in 96-97 % of fractions for all translational directions and intrafraction lesion motion was limited to 3 mm in 97-100 % of fractions. Para-rectal lesions (11 %) were associated with significantly larger inter- and intrafraction motion compared to other pelvic locations and treatment duration showed no correlation with lesion motion. The mean (sd) lesion inclusiveness index was 99 % (5 %) for the 5-mm PTV margin and 96 % (9 %) for the 3-mm margin. Conclusion: Pelvic lymph node motion during CBCT-guided stereotactic radiotherapy was within the widely applied PTV margin of 5 mm, providing an opportunity to reduce this margin for pelvic lymph node SBRT. Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: The ADOPT clinical trial (Principal Investigator S. Aluwini, NCT04302454) has been funded by the Dutch Cancer Society (KWF, Amsterdam, Grant number 12448). The department of Radiation Oncology of the University Medical Center Groningen has research contracts with IBA, RaySearch, Siemens, Elekta, Leoni, and Mirada, and has received grants from the Dutch Cancer Society and the European Union. (© 2024 The Authors.)
Databáze:	MEDLINE
Externí odkaz:	Zobrazit plný text záznamu