Cascade-based Pancreatic Tumor Segmentation via Interactive Enhancement and Fine Localization

Accurate delineation of pancreatic tumors in computed tomography (CT) images is essential for timely diagnosis, guiding therapeutic strategies, and predicting clinical outcomes in pancreatic cancer. However, the small size, irregular morphology, and complex spatial context of pancreatic tumors pose significant challenges for conventional segmentation methods, often leading to misclassification or omission of tumor regions. To address these limitations, we propose a coarse-to-fine dual-stage segmentation framework. In the first stage, a coarse segmentation network, built on a multi-scale backbone, extracts preliminary tumor regions by leveraging rich contextual features. These coarse predictions are refined by an interaction enhancement module that transforms initial visual cues into tumor-aware priors and spatial weights to localize and crop tumor candidates. In the second stage, a fine segmentation network equipped with a class-aware boundary-refinement loss further enhances the delineation of small tumor structures and inter-class boundaries. Extensive experiments on a benchmark pancreatic tumor dataset demonstrate that our framework achieves superior performance, with an average DSC of 60.24%, consistently outperforming existing baselines and highlighting the effectiveness of the proposed approach.