Optimization of brain tumours irradiation : determining the set-up margin

Žager Marciuš, Valerija (author), Dolenc, Laura (author), Smrdel, Uroš (author)

The aim of this work was to evaluate whether the excising margin of the clinical tumor volume and planning target volume correspond with calculated radiation margin based on systematic errors, and definition of radiation margins of individual brain lobes. This research was a retrospective cross-sectional study. We checked the systematic errors and calculated their average and the size of radiation margins. The average systematic errors were calculated in four directions: lateral, longitudinal, vertical, and rotation. The largest average systematic error was calculated in the lateral direction in the cerebellar area, and the error was also statistically significant (p < 0.05). In rotational direction we notice the statistically significant difference in frontal lobe (p = 0.037), and cerebellar area (p = 0.002). The largest safety margin, as measured by the average systematic errors, is required for irradiation of the cerebellum. The safety margin size of 6.94 mm was calculated according to the formula of Van Herk. However, the smallest safety margin can be used for irradiation of the occipital lobe of the brain, namely 4.85 mm. The linear regression results that only cerebellar lesions affect lateral displacements. Based on our calculation of the mean systematic errors, we estimate that the clinical target volume – planning target volume safety margin can't be reduced further from the current 5 mm to a size of 3 mm without the use of image guided radiotherapy.

• Language: English
• Keywords: brain tumor, geometric verification of radiation, modern radiation therapy technique, radiation treatment margin, radiotherapy
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: ZF - Faculty of Health Sciences
• Publication status: Published
• Publication version: Version of Record
• Publication date: 01.01.2022
• Year: 2022
• Number of pages: Str. 235-240
• Numbering: Vol. 37, no. 3
• PID: 20.500.12556/RUL-144280
• UDC: 616-073:615.849
• ISSN on article: 1451-3994
• DOI: 10.2298/NTRP2203235Z
• COBISS.SI-ID: 141099523
• Publication date in RUL: 09.02.2023

Record is a part of a journal

• Title: Nuclear Technology & Radiation Protection
• Shortened title: Nucl. Technol. Radiat. Prot.
• Publisher: Vinča Instituta of Nuclear Sciences
• ISSN: 1451-3994
• COBISS.SI-ID: 18296103

Licences

• License: CC BY-NC-ND 3.0, Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported
• Link: http://creativecommons.org/licenses/by-nc-nd/3.0/
• Description: You are free to reproduce and redistribute the material in any medium or format. You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use. You may not use the material for commercial purposes. If you remix, transform, or build upon the material, you may not distribute the modified material. You may not apply legal terms or technological measures that legally restrict others from doing anything the license permits.
• Licensing start date: 06.02.2023

Secondary language

• Language: Undetermined
• Keywords: možganski tumor, geometrijska verifikacija obsevanja, sodobna tehnika obsevanja, rob obsevanja, radioterapija