Radiologic Progression Types Are Treatment Specific: An Exploratory Analysis Of A Phase 3 Study Of Bevacizumab Plus Radiotherapy Plus Temozolomide For Patients With Newly Diagnosed Glioblastoma (Avaglio).

2048Background: Thetype of radiological progression following bevacizumab treatment failure is related to outcome in patients with progressive glioblastoma. In an exploratory analysis of the randomized, placebo-controlled phase III clinical trial in newly diagnosed glioblastoma of bevacizumab (bev) plus radiotherapy/temozolomide (AVAglio) we aimed to investigate whether these progression types (PT) are induced by therapy (anti-angiogenic versus sole cytotoxic chemotherapy), are related to outcome and may therefore reflect a particular resistance mechanism. Methods: MRI scans (baseline until IRF progress) of 621 patients (bev arm, n = 299; placebo arm, n = 322) were available for analysis in sufficient detail and quality. PT were categorized according to contrast enhancement behavior in T1 and T2 hyper-intense signal change as published before (Nowosielski et al, Neurology 2014). Frequencies of the 5 PTs (cT1 flare-up, classic T1 progress, T2-diffuse, T2-circumscribed and primary non-responder), time to de...