Re-irradiation for recurrent glioblastoma multiforme

Abstract

Background/Aim: Patients requiring re-irradiation for recurrent glioblastoma multiforme (GBM) may benefit from individualized therapy. This study aimed to identify predictors of survival and contribute to treatment personalization. Patients and Methods: In 28 patients with recurrent GBM, nine factors were analyzed for associations with survival: Main location and type of recurrence, Karnofsky performance score (KPS), age, gender, interval between primary radiotherapy and recurrence, gross total resection (GTR), equivalent dose in 2-Gy fractions (EQD2) of re-irradiation and cumulative EQD2 of primary and re-irradiation. Results: On univariate analyses, GTR (p=0.047), EQD2 ≥30 Gy (p=0.029) and cumulative EQD2 ≥90 Gy (p=0.023) were significantly associated with better survival; frontal location (p=0.119) and KPS 80-100% (p=0.067) showed trends. In multivariate analyses, frontal location (p=0.032) and cumulative EQD2 ≥90 Gy (p=0.038) were significant; KPS 80-100% (p=0.110) and EQD2 ≥30 Gy (p=0.083) showed trends. Conclusion: Predictors of survival after re-irradiation for recurrent GBM were identified that can help when designing personalized treatments. Use of irradiation with EQD2 ≥30 Gy appeared superior to lower doses.