Impact of clinical target volume margin reduction in glioblastoma patients treated with concurrent chemoradiation.

Autor: Di Perri D; Department of Radiation Oncology, Cliniques Universitaires Saint-Luc, Brussels, Belgium., Hofstede D; Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands., Hartgerink D; Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands., Terhaag K; Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands., Houben R; Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands., Postma AA; Department of Radiology and Nuclear Medicine, Maastricht University Medical Center+, MHeNs School for Mental Health and Neuroscience, Maastricht, The Netherlands., Hoeben A; Division of Medical Oncology, Department of Internal Medicine, GROW-School of Oncology and Developmental Biology, Maastricht University Medical Center+, Maastricht, The Netherlands., Anten M; Department of Neurology, GROW School for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands., Ackermans L; Department of Neurosurgery, Maastricht University Medical Centre+, Maastricht, The Netherlands., Compter I; Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands., Eekers DBP; Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands.
Jazyk: angličtina
Zdroj: Neuro-oncology practice [Neurooncol Pract] 2023 Oct 27; Vol. 11 (3), pp. 249-254. Date of Electronic Publication: 2023 Oct 27 (Print Publication: 2024).
DOI: 10.1093/nop/npad071
Abstrakt: Background: Glioblastoma (GBM) is widely treated using large radiotherapy margins, resulting in substantial irradiation of the surrounding cerebral structures. In this context, the question arises whether these margins could be safely reduced. In 2018, clinical target volume (CTV) expansion was reduced in our institution from 20 to 15 mm around the gross target volume (GTV) (ie, the contrast-enhancing tumor/cavity). We sought to retrospectively analyze the impact of this reduction.
Methods: All adult patients with GBM treated between January 2015 and December 2020 with concurrent chemoradiation (60Gy/2Gy or 59.4Gy/1.8Gy) were analyzed. Patients treated using a 20 (CTV 20 , n  = 57) or 15 mm (CTV 15 , n  = 56) CTV margin were compared for target volumes, dose parameters to the surrounding organs, pattern of recurrence, and survival outcome.
Results: Mean GTV was similar in both groups (ie, CTV 20 : 39.7cm 3 ; CTV 15 : 37.8cm 3 ; P  = .71). Mean CTV and PTV were reduced from 238.9cm 3 to 176.7cm 3 ( P  = .001) and from 292.6cm 3 to 217.0cm 3 ( P  < .001), for CTV 20 and CTV 15 , respectively. As a result, average brain mean dose (D mean ) was reduced from 25.2Gy to 21.0Gy ( P  = .002). Significantly lower values were also observed for left hippocampus D mean , brainstem D 0.03cc , cochleas D mean , and pituitary D mean . Pattern of recurrence was similar, as well as patient outcome, ie, median progression-free survival was 8.0 and 7.0 months ( P  = .80), and median overall survival was 11.0 and 14.0 months ( P  = .61) for CTV 20 and CTV 15 , respectively.
Conclusions: In GBM patients treated with chemoradiation, reducing the CTV margin from 20 to 15 mm appears to be safe and offers the potential for less treatment toxicity.
Competing Interests: None.
(© The Author(s) 2023. Published by Oxford University Press on behalf of the Society for Neuro-Oncology and the European Association of Neuro-Oncology. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)
Databáze: MEDLINE
Externí odkaz: