1. Re-irradiation for recurrent glioblastoma: a pattern of care analysis.
- Author
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Rogers S, Gross M, Ermis E, Cosgun G, Baumert BG, Mader T, Schroeder C, Lomax N, Alonso S, Ademaj A, Lazeroms T, Lee SY, Mayinger M, Mamot C, Schwyzer L, Schubert GA, and Riesterer O
- Subjects
- Humans, Female, Middle Aged, Male, Aged, Adult, Switzerland epidemiology, Practice Patterns, Physicians' statistics & numerical data, Aged, 80 and over, Glioblastoma radiotherapy, Brain Neoplasms radiotherapy, Neoplasm Recurrence, Local, Re-Irradiation methods
- Abstract
Background: 90% of glioblastomas (GBM) relapse within two years of diagnosis. In contrast to the initial setting, there is no standard management for recurrent disease and options include hypofractionated stereotactic re-irradiation (re-mHSRT). The aims of this study were to investigate re-mHSRT practice in Swiss neuro-oncology centres., Methods: A survey of 18 questions regarding re-irradiation for GBM was created and distributed electronically (SurveyMonkey, USA) to 11 radiation oncologists in Switzerland specialising in brain tumours. We evaluated the clinical outcomes of a multicentre series of patients treated with an established re-mHSRT schedule to benchmark these against the literature and investigated the radiological patterns of relapse after re-mHSRT., Results: 8 of 11 (73%) radiation oncologists responded to the survey and re-irradiation practice was heterogeneous. The 10 × 3.5 Gy schedule (RTOG 1205, BRIOChe trials) was used by 5/8 respondents and 47/50 patients with recurrent GBM treated with re-mHSRT with this schedule in daily practice were included in the analysis. The median time to re-mHSRT following completion of adjuvant RT was 23.3 (7-224) months. The median PTV at re-mHSRT was 22.0 cm
3 (0.9-190). Combined CTV + PTV margins ranged from 0 to 10 mm and median prescription isodose was 80% (67-100). 14/47 (30%) patients received temozolomide and four (8.5%) continued bevacizumab concomitantly. On multivariable analysis, concomitant systemic therapy predicted for progression-free survival (PFS), HR 2.87 (95% CI 1-03-7.96), p = 0.042. Median PFS following re-mHSRT was 6.6 (0.2-92.5) months and 26/47 patients (55%) received subsequent systemic therapy. The median overall survival (OS) following recurrence was 11.8 months (1.5-92.5), similar to the 10.8 months in the literature with the same schedule. The six-month OS rate was 37/47 (79%), which compares well with the 73% reported in a meta-analysis of 50 publications employing various schedules. In a subgroup analysis of 36/47 (79%) patients with MR follow-up after re-mHSRT, 8/36 (22%) had no radiological evidence of tumour progression at a median follow-up of 9.4 months. 21/28 (75%) radiological relapses were in-field, two were marginal and five were out of field., Conclusions: Re-mHSRT with 10 × 3.5 Gy can achieve local control in selected patients with recurrent GBM., Competing Interests: Declarations. Ethics approval and consent to participate: Ethics committee approval for the multicentre analysis was obtained from the Ethikkommission Nordwest und Zentral Schweiz (EKNZ 2023 − 00414). Patients provided informed consent for both medical therapy and consent for use of anonymised data in ethics-approved future research projects. Patients treated prior to introduction of this consent form in 2018 could not be asked. Consent for publication: Covered by the consent obtained. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)- Published
- 2024
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