The aim of this study was to evaluate the efficacy of re-irradiation in patients with recurrent gliomas and to identify subgroups for whom re-irradiation for recurrent gliomas is most beneficial.

We retrospectively reviewed 36 patients with recurrent or progressive gliomas who received re-irradiation between January 1996 and December 2011. Re-irradiation was offered to recurrent glioma patients with good performance or at least 6 months had passed after initial radiotherapy (RT), with few exceptions.

Median doses of re-irradiation and initial RT were 45.0 Gy and 59.4 Gy, respectively. The median time interval between initial RT and re-irradiation was 30.5 months. Median overall survival (OS) and the 12-month OS rate were 11 months and 41.7%, respectively. In univariate analysis, Karnofsky performance status (KPS) ≥70 (p<0.001), re-irradiation dose ≥45 Gy (p=0.040), and longer time interval between initial RT and re-irradiation (p=0.040) were associated with improved OS. In multivariate analysis, KPS (p=0.030) and length of time interval between initial RT and re-irradiation (p=0.048) were important predictors of OS. A radiographically suspected mixture of radiation necrosis and progression after re-irradiation was seen in 5 patients.

Re-irradiation in conjunction with surgery could be a salvage treatment for selected recurrent glioma patients with good performance status and recurrence over a long time.