Purpose Positron emission tomography (PET) is increasingly used in neuro-oncology. However, little is known about its application across European institutions and reasons for variable implementation. Methods Between June and August 2024, members of the European Organisation for Research and Treatment of Cancer - Brain Tumour Group (EORTC-BTG) completed a cross-sectional online survey on PET use in neuro-oncological practice. Results Overall, 103 replies from 20 countries were received. A PET facility was available at 96/103 (93.2%) sites, of whom 74 (77.1%) performed PET in patients with brain tumours. Reasons for not performing PET included limited availability of tracers (14/29, 48.3%), high cost (11/29, 37.9%), and PET perceived unnecessary (8/29, 27.6%). Of sites performing PET, 69/74 (93.2%) reported use in glioma, 58/74 (78.4%) in brain metastasis, 52/74 (70.3%) in meningioma, and 46/74 (62.2%) in CNS lymphoma. Amino acid PET was performed at 62/71 centres (87.3%; 3 not reported [n.r.]), most frequently in glioma (58/59, 98.3%, 3 n.r.) and for differentiation of treatment-related changes from tumour progression (58/59, 98.3%). Somatostatin receptor (SSTR) PET was performed at 50/68 sites (73.5%, 6 n.r.), mainly in meningioma (48/49, 98.0%), for patient selection before radioligand therapy (41/49, 83.7%) and for radiotherapy target volume definition (33/49, 67.3%). Unrestricted coverage by statutory health insurance was reported by 46/59 (78.0%) centres for amino acid PET and 33/49 (67.3%) for SSTR PET. Conclusion PET use in neuro-oncology is variable across EORTC-BTG sites. Generation of evidence in clinical trials and surveys including non-academic institutions are needed to guide implementation in clinical practice.

Purpose The prognosis of diffuse gliomas previously classified as “lower-grade” is heterogeneous and complicates clinical decisions. We aimed to investigate the molecular profile of clinical outliers ...