BMC Neurology (Nov 2024)

Re-irradiation for recurrent glioblastoma: a pattern of care analysis

  • Susanne Rogers,
  • Markus Gross,
  • Ekin Ermis,
  • Gizem Cosgun,
  • Brigitta G. Baumert,
  • Thomas Mader,
  • Christina Schroeder,
  • Nicoletta Lomax,
  • Sara Alonso,
  • Adela Ademaj,
  • Tessa Lazeroms,
  • Seok-Yun Lee,
  • Michael Mayinger,
  • Christoph Mamot,
  • Lucia Schwyzer,
  • Gerrit A. Schubert,
  • Oliver Riesterer

DOI
https://doi.org/10.1186/s12883-024-03954-z
Journal volume & issue
Vol. 24, no. 1
pp. 1 – 9

Abstract

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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 cm3 (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.

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