Toxicity and efficacy of re-irradiation of high-grade glioma in a phase I dose- and volume escalation trial

Publication date: Available online 17 October 2017
Source:Radiotherapy and Oncology
Author(s): Søren Møller, Per Munck af Rosenschöld, Junia Costa, Ian Law, Hans Skovgaard Poulsen, Svend Aage Engelholm, Silke Engelholm
IntroductionThe purpose of this study was to evaluate the safety and efficacy of PET and MRI guided re-irradiation of recurrent high-grade glioma (HGG) and to assess the impact of radiotherapy dose, fractionation and irradiated volume.Material and methodsPatients with localized, recurrent HGG (grades III-IV) and no other treatment options were eligible for a prospective phase I trial. Gross tumor volumes for radiotherapy were defined using T1-contrast enhanced MRI and ¹⁸F-fluoro-ethyl tyrosine PET. Radiotherapy was delivered using volumetric modulated arc therapy with a 2-mm margin. The dose prescription of four consecutive groups was (1) 35 Gy/10fr., (2) 42 Gy/10fr., (3) 29.5 Gy/5fr. and (4) 35 Gy/10fr. to larger tumor volumes (100–300 cm³), respectively.ResultsThirty-one patients were treated of which 81% had glioblastoma. The median progression-free survival was 2.8 months (95%CI: 2.1–3.5) and the median overall survival was 7.0 months (95%CI: 3.5–10.5). Early side effects were mild and included headache and fatigue. Seven patients were progression-free beyond 10 weeks and were evaluable for late toxicity. Among these patients, three (43%) suffered late adverse events which included radionecrosis and irreversible white matter changes.ConclusionRe-irradiation showed limited efficacy and 43% of patients achieving disease control suffered late toxicity that was manageable but not negligible.



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