Multidisciplinary consensus recommendations for the management of IDH-mutant grade 2 gliomas in Spain: a Delphi study

PURPOSE: Management of IDH-mutant grade 2 gliomas is challenging due to tumor heterogeneity and uncertainties arising from new imaging modalities, diagnostic advances, and emerging targeted therapies. This study aimed to develop multidisciplinary consensus recommendations to standardize the diagnosis, treatment, and follow-up of these gliomas in Spain. METHODS: A multidisciplinary scientific committee drafted 85 clinical statements based on literature and expert experience. These were independently rated through two rounds of an online Delphi survey by a panel of 18 experts, including three representatives from each of six Spanish scientific societies involved in neuro-oncology, neurosurgery, neuropathology, radiation oncology, neuroradiology, and medical oncology. RESULTS: After two rounds, consensus was achieved on 74 statements (87.1%). Key agreements included magnetic resonance imaging (MRI) with gadolinium and advanced imaging as preferred diagnostics; mandatory molecular testing for IDH1/2 mutations and 1p/19q codeletion; individualized risk stratification guiding treatment; maximal safe surgical resection as first-line management; and combined chemoradiotherapy for high-risk patients. The IDH1/2 inhibitor vorasidenib is recognized as an emerging therapy for patients with grade 2 glioma. Areas without consensus involved liquid biopsy and specific clinical scenarios for vorasidenib. Emphasis was placed on multidisciplinary decision-making and long-term toxicity monitoring. CONCLUSIONS: This work delivers multidisciplinary consensus recommendations to standardize care in IDH-mutant grade 2 gliomas, integrating advances in molecular diagnostics, imaging, and therapeutics. It also identifies key knowledge gaps and clinical uncertainties, underscoring the critical need for ongoing research and expert collaboration to continually refine personalized management approaches and improve patient outcomes.