Reirradiation of relapsed Glioblastoma
Dr Anthony Falkov, Auckland Radiation Oncology, 100 Mountain Road Epsom Auckland
Re-irradiation of Recurrent High Grade Gliomas
Most high grade gliomas (HGG) recur locally and at recurrence no standard treatment exists, options include re-resection, salvage systemic therapy, and re-irradiation. All options have similar survival rates, albeit different toxicities. This retrospective study evaluates patients who underwent re-irradiation for recurrent HGGs.
From 2009 to 2014, 82 patients were retrospectively identified who underwent re-irradiation for HGG. The patient’s survival from re-irradiation was the primary endpoint. Re-irradiation consisted of either standard radiotherapy of 3D conformal or IMRT, or hypofractionated stereotactic radiotherapy utilising VMAT. Survival was estimated via the Kaplan-Meier method with differences assessed via the log-rank test, and hazard ratios (HR) were estimated using Cox regression analysis.
Median overall survival from re-irradiation was 9.5 months. The best prognostic subgroups had a 36% survival at 33 months. Re-irradiation, to a median dose 35Gy/10#, was well tolerated, 4% developing grade 3 toxicity, none grade ≥4, and no radiation brain necrosis . On the multivariate analysis, factors significantly associated with survival included: months from initial radiotherapy (HR=0.98, 95% CI=0.96-0.99); performance status at re-irradiation of >= 2 vs 0-1 ; multifocal vs unifocal recurrence ; and total re-irradiation dose ≥35Gy vs < 35Gy .
Repeat resection, salvage systemic therapy, and age were unrelated to survival.
Patients with recurrent HGG tolerated re-irradiation well and in good prognostic groups, have an estimated survival of 20-36% at 30 months. This study suggests follow up of HGG patients with regular MRI scans, and instituting salvage therapy like re-irradiation when performance status is best.
KEYWORDS: glioma, glioblastoma, radiotherapy, recurrent, re-irradiationFormat: Oral communication