Blood-based biomarkers for mild traumatic brain injury: European recommendations and real-world practice in Belgium

Blood‑based biomarkers such as S100B and GFAP + UCH‑L1 have demonstrated high sensitivity for ruling out intracranial injury in mild traumatic brain injury (mTBI). To describe and compare international guidelines on biomarker use in mTBI, identify key similarities and differences, and describe Belgian diagnostic practices, including Computed Tomography (CT) utilisation and attitudes toward biomarker adoption. A pragmatic search of the published and grey literature identified European guidelines or recommendations on integrating blood‑based biomarkers in the management of mTBI. A 2025 questionnaire was sent to heads of Belgian emergency departments to document CT utilisation, application of clinical decision rules, biomarker awareness, perceived utility, and implementation barriers. Guidance varies considerably across Europe. NICE (UK) does not endorse biomarkers due to insufficient evidence; Scandinavian recommendations support S100B in low‑risk adults; French guidelines recommend S100B and GFAP + UCH‑L1 in intermediate‑risk adults; Spanish guidance and a 2024 European consensus support biomarker use as CT‑sparing tools in selected adults. Approximately one‑third of Belgian hospitals responded to our survey. Adult CT utilisation was high (~60%) with substantial inter‑hospital variability; paediatric CT rates were generally <20%. Clinical decision rules were inconsistently used (PECARN in children; CCHR and SF in adults). Only one centre reported using S100B. Around 39% of clinicians were unfamiliar with biomarkers, citing lack of training, absent national guidance or reimbursement, workflow constraints, and medico‑legal concerns. Although several international recommendations support biomarker use as CT alternatives, Belgian adoption remains limited, with considerable variability in diagnostic pathways. National standardisation and adoption of a validated clinical algorithm may facilitate appropriate integration. Not applicable.