Re-Irradiation for Recurrent Glioblastoma Multiforme.

Abstract

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. 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. 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. 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.