Efficacy of intra-arterial chemotherapy across intracranial tumors: A systematic review and meta-analysis

PURPOSE: Intra-arterial chemotherapy (IAC) is used to increase the delivery of chemotherapy agents for intracranial tumours, but its clinical value across diseases remains uncertain. We evaluated the clinical outcomes of IAC across intracranial tumours. METHODS: We systematically searched PubMed, Embase, Scopus and Web of Science until April 2025 (PROSPERO CRD420251056066). Eligible clinical studies evaluated IAC as primary, neoadjuvant, concurrent or salvage therapy and reported quantitative outcomes. For time-to-event outcomes we preferentially extracted and reconstructed hazard ratios (HRs). Random-effects meta-analysis was undertaken where comparable data permitted; small-study effects were explored with funnel plots and Egger's test. RESULTS: Of 1302 records, 155 studies were included in the qualitative synthesis (retinoblastoma, malignant gliomas, head-and-neck squamous-cell carcinoma (HNSCC), and other tumours). IAC achieved high globe-salvage with low systemic toxicity in retinoblastoma. However, in gliomas and skull-based HNSCC, radiographic responses occurred in subsets. A meta-analysis of four studies in glioma showed no significant difference in survival (pooled HR 1.07, 95 % CI 0.95-1.21; prediction interval 0.70-1.65), with evidence of funnel-plot asymmetry (Egger's p = 0.001). Between-study heterogeneity was extreme, and most studies were at serious or critical risk of bias. Toxicities were regimen-dependent, and catheter-related neurovascular events were uncommon. CONCLUSIONS: Current evidence supports the role of IAC in ocular retinoblastoma. For gliomas, HNSCC and other skull-base tumors, IAC remains investigational where survival benefit over systemic therapy is unproven. Generally, the pharmacologic advantages of IA delivery alone have not translated into a consistent survival benefit outside retinoblastoma.