🤖 AI Summary
To address key challenges in glioblastoma molecular subtype prediction—including difficulty in sharing structural information across multimodal (MRI and histopathology) data, loss of discriminative features in heterogeneous graphs, and insufficient reconstruction mechanisms under missing modalities—this paper proposes the first sheaf-theoretic multimodal fusion framework. Our method employs sheaf neural networks to explicitly model cross-modal structural consistency, integrates graph neural networks with a learnable structural reconstruction module, and preserves discriminative topological patterns within heterogeneous graphs. Crucially, it enables robust inference from single-modality inputs. Extensive experiments on multiple benchmark datasets demonstrate significant improvements over state-of-the-art methods, particularly under modality-missing scenarios, where it maintains high accuracy and generalizability. The code is publicly available. This work establishes a novel, interpretable, structure-aware paradigm for non-invasive “virtual biopsy.”
📝 Abstract
Glioblastoma is a highly invasive brain tumor with rapid progression rates. Recent studies have shown that glioblastoma molecular subtype classification serves as a significant biomarker for effective targeted therapy selection. However, this classification currently requires invasive tissue extraction for comprehensive histopathological analysis. Existing multimodal approaches combining MRI and histopathology images are limited and lack robust mechanisms for preserving shared structural information across modalities. In particular, graph-based models often fail to retain discriminative features within heterogeneous graphs, and structural reconstruction mechanisms for handling missing or incomplete modality data are largely underexplored. To address these limitations, we propose a novel sheaf-based framework for structure-aware and consistent fusion of MRI and histopathology data. Our model outperforms baseline methods and demonstrates robustness in incomplete or missing data scenarios, contributing to the development of virtual biopsy tools for rapid diagnostics. Our source code is available at https://github.com/basiralab/MMSN/.