Abstract
BACKGROUND: Our objective was to report current neuroimaging classification systems of spatial patterns of progression in glioblastoma, report the terminology used to describe ‘progression’ and to assess the compliance of these studies with the Response Assessment in Neuro-Oncology (RANO) Criteria. METHODS: We conducted a systematic review to identify all neuroimaging studies of glioblastoma that have employed a categorical classification system of spatial progression patterns. Our review was registered with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) registry. RESULTS: From the included 157 results, we identified 129 studies that used labels of spatial progression patterns that were not (Group 1) and 50 studies that used labels that were based on radiation volumes. In Group 1, we found 113 individual labels and the most frequent were: local/localised (58%), distant/distal (51%), diffuse (20%), multifocal (15%) and subependymal/subventricular zone (15%). We identified 13 different labels used to refer to ‘progression’, of which the most frequent were ‘recurrence’ (99%) and ‘progression’ (92%). We identified 37% (n=33/90) of studies published following the release of the RANO classification were adherent compliant with the RANO criteria. CONCLUSIONS: Our review reports significant heterogeneity in the published systems used to classify glioblastoma spatial progression patterns. Standardisation of terminology and classification systems used in studying progression with neuroimaging would increase the efficiency of our research in our attempts to more successfully treat glioblastoma.