ViLa-MIL: Dual-scale Vision-Language Multiple Instance Learning for Whole Slide Image Classification
Authors: Jiangbo Shi, Chen Li, Tieliang Gong, Yefeng Zheng, Huazhu Fu

Multiple instance learning (MIL)-based framework has become the mainstream for processing the whole slide image (WSI) with giga-pixel size and hierarchical image context in digital pathology. However these methods heavily depend on a substantial number of bag-level labels and solely learn from the original slides which are easily affected by variations in data distribution. Recently vision language model (VLM)-based methods introduced the language prior by pre-training on large-scale pathological image-text pairs. However the previous text prompt lacks the consideration of pathological prior knowledge therefore does not substantially boost the model's performance. Moreover the collection of such pairs and the pre-training process are very time-consuming and source-intensive. To solve the above problems we propose a dual-scale vision-language multiple instance learning (ViLa-MIL) framework for whole slide image classification. Specifically we propose a dual-scale visual descriptive text prompt based on the frozen large language model (LLM) to boost the performance of VLM effectively. To transfer the VLM to process WSI efficiently for the image branch we propose a prototype-guided patch decoder to aggregate the patch features progressively by grouping similar patches into the same prototype; for the text branch we introduce a context-guided text decoder to enhance the text features by incorporating the multi-granular image contexts. Extensive studies on three multi-cancer and multi-center subtyping datasets demonstrate the superiority of ViLa-MIL.