External beam radiation dose escalation for high grade glioma

• Published in: Cochrane database of systematic reviews 2020-05, Vol.5 (5), p.CD011475
• Main Authors: Khan, Luluel, Soliman, Hany, Sahgal, Arjun, Perry, James, Xu, Wei, Tsao, May N
• Format: Article
• Language: English
• Subjects: Adult; Age Factors; Aged; Brain Neoplasms - mortality; Brain Neoplasms - pathology; Brain Neoplasms - radiotherapy; Cancer; Cranial Irradiation - methods; Cranial Irradiation - mortality; Disease-Free Survival; Dose Fractionation, Radiation; Glioma - mortality; Glioma - pathology; Glioma - radiotherapy; Humans; Middle Aged; NEURO-ONCOLOGY; Neurology; Quality of Life; Randomized Controlled Trials as Topic; Survival Analysis
• ISSN: 1469-493X; 1469-493X
• DOI: 10.1002/14651858.CD011475.pub3

This is an updated version of the original Cochrane Review published in Issue 8, 2016. High grade glioma (HGG) is a rapidly growing brain tumour in the supporting cells of the nervous system, with several subtypes such as glioblastoma (grade IV astrocytoma), anaplastic (grade III) astrocytoma and anaplastic (grade III) oligodendroglioma. Studies have investigated the best strategy to give radiation to people with HGG. Conventional fractionated radiotherapy involves giving a daily radiation dose (called a fraction) of 180 cGy to 200 cGy. Hypofractionated radiotherapy uses higher daily doses, which reduces the overall number of fractions and treatment time. Hyperfractionated radiotherapy which uses a lower daily dose with a greater number of fractions and multiple fractions per day to deliver a total dose at least equivalent to external beam daily conventionally fractionated radiotherapy in the same time frame. The aim is to reduce the potential for late toxicity. Accelerated radiotherapy (dose escalation) refers to the delivery of multiple fractions per day using daily doses of radiation consistent with external beam daily conventionally fractionated radiotherapy doses. The aim is to reduce the overall treatment time; typically, two or three fractions per day may be delivered with a six to eight hour gap between fractions. To assess the effects of postoperative external beam radiation dose escalation in adults with HGG. We searched CENTRAL, MEDLINE Ovid and Embase Ovid to August 2019 for relevant randomised phase III trials. We included adults with a pathological diagnosis of HGG randomised to the following external beam radiation regimens: daily conventionally fractionated radiotherapy versus no radiotherapy; hypofractionated radiotherapy versus daily conventionally fractionated radiotherapy; hyperfractionated radiotherapy versus daily conventionally fractionated radiotherapy or accelerated radiotherapy versus daily conventionally fractionated radiotherapy. The primary outcomes were overall survival and adverse effects. The secondary outcomes were progression free survival and quality of life. We used the standard methodological procedures expected by Cochrane. We assessed the certainty of the evidence using the GRADE approach. Since the last version of this review, we identified no new relevant trials for inclusion. We included 11 randomised controlled trials (RCTs) with 2062 participants and 1537 in the relevant arms for this review. There was an overall