Elsevier

Practical Radiation Oncology

Volume 6, Issue 4, July–August 2016, Pages 217-225
Practical Radiation Oncology

Special Article
Radiation therapy for glioblastoma: Executive summary of an American Society for Radiation Oncology Evidence-Based Clinical Practice Guideline

https://doi.org/10.1016/j.prro.2016.03.007Get rights and content

Abstract

Purpose

To present evidence-based guidelines for radiation therapy in treating glioblastoma not arising from the brainstem.

Methods and materials

The American Society for Radiation Oncology (ASTRO) convened the Glioblastoma Guideline Panel to perform a systematic literature review investigating the following: (1) Is radiation therapy indicated after biopsy/resection of glioblastoma and how does systemic therapy modify its effects? (2) What is the optimal dose-fractionation schedule for external beam radiation therapy after biopsy/resection of glioblastoma and how might treatment vary based on pretreatment characteristics such as age or performance status? (3) What are ideal target volumes for curative-intent external beam radiation therapy of glioblastoma? (4) What is the role of reirradiation among glioblastoma patients whose disease recurs following completion of standard first-line therapy? Guideline recommendations were created using predefined consensus-building methodology supported by ASTRO-approved tools for grading evidence quality and recommendation strength.

Results

Following biopsy or resection, glioblastoma patients with reasonable performance status up to 70 years of age should receive conventionally fractionated radiation therapy (eg, 60 Gy in 2-Gy fractions) with concurrent and adjuvant temozolomide. Routine addition of bevacizumab to this regimen is not recommended. Elderly patients (≥ 70 years of age) with reasonable performance status should receive hypofractionated radiation therapy (eg, 40 Gy in 2.66-Gy fractions); preliminary evidence may support adding concurrent and adjuvant temozolomide to this regimen. Partial brain irradiation is the standard paradigm for radiation delivery. A variety of acceptable strategies exist for target volume definition, generally involving 2 phases (primary and boost volumes) or 1 phase (single volume). For recurrent glioblastoma, focal reirradiation can be considered in younger patients with good performance status.

Conclusions

Radiation therapy occupies an integral role in treating glioblastoma. Whether and how radiation therapy should be applied depends on characteristics specific to tumor and patient, including age and performance status.

Cited by (0)

Presented at the 57th ASTRO Annual Meeting, October 18-21, 2015, San Antonio, TX.

Conflicts of interest: Before initiating work on this guideline, all panelists completed disclosure statements and pertinent disclosures are published within this report. Where potential conflicts are detected, remedial measures to address them are taken and noted here.

Dr Kirkpatrick receives research funding, honoraria, and travel expenses from Varian; is a partner in ClearSight Radiotherapy Products; and received previous research funding from Genentech. Dr Fiveash receives honoraria, travel expenses, and research funding from Varian. Dr Shig serves on an advisory board for Genentech and received previous honoraria and travel expenses from Merck. Dr Koay receives research funding from Phillips and has a pending patent on quantitative pancreatic image analysis. Dr Lutz had previous stock in Tosk and Oculus. Dr Vogelbaum is a consultant for NeuralStem and has stock options, royalties, and patent licensing and copyright fees from Infuseon. Dr Reardon serves on advisory boards for Roche/Genentech, EMD Serono, Novartis, Amgen, Abbvie, Bristol-Myers Squibb, Cavion, Celldex, Juno Pharmaceuticals, Momenta Pharmaceuticals, Novocure, Oxigene, Regeneron, and Stemline; served on a previous advisory board for Apogenix; is on speaker bureaus for Merck/Scherin and Roche/Genentech; and receives research funding from Celldex, Inovio, and Midatech. Dr Wen is on advisory boards for Roche/Genentech, Novartis, Regeneron, Monteris, and Cavion; is a speaker for Merck; is steering committee chair for Vascular Biogenics trial; and was previously on advisory boards for Abbvie, Cubist, Foundation Medicine, Merck, and Midatech. Dr Chang receives honoraria from Abbvie BrainLab, and Elekta.

The panel chairs and American Society for Radiation Oncology Guidelines Subcommittee reviewed these disclosures and took measures to mitigate the impact of potential conflicts. Because of relationships with Merck, Drs Reardon, Shih, and Wen did not write the recommendations and narratives addressing temozolomide and were recused from consensus voting on these recommendations. Because of relationships with Genentech, Drs Reardon, Wen, and Kirkpatrick did not write the recommendations and narratives regarding bevacizumab and were recused from voting on these recommendations. No other disclosures were viewed as affecting guideline content.

Supplementary material for this article (http://dx.doi.org/10.1016/j.prro.2016.03.007) can be found at www.practicalradonc.org.

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