CT Habitat-peritumoral fusion radiomics predicts aggressiveness and prognosis in pheochromocytomas and paragangliomas to inform intensified surgical strategies: A multicenter study.

BACKGROUND

This study aimed to develop a dual-domain radiomics framework integrating probability-driven high-risk habitats and peritumoral microenvironmental features to accurately predict the aggressiveness of pheochromocytomas and paragangliomas (PPGLs).

METHODS

This retrospective study included 356 patients with abdominal PPGLs from four institutions, who were divided into a training set (n = 182) and two external test sets (n = 70, n = 104). Radiomic features were extracted from the whole-tumor and 1-mm peritumoral regions on contrast-enhanced CT images. Probability-driven habitat analysis utilizing a Support Vector Machine and K-means clustering was implemented to segment high-risk subregions. Following rigorous cascaded feature selection, a Random Forest-based fusion model was constructed to integrate key habitat and peritumoral features for predicting aggressiveness. Additionally, SHapley Additive exPlanations (SHAP) analysis was employed to evaluate feature importance and model interpretability.

RESULTS

The habitat-peritumoral fusion model demonstrated superior predictive performance and robustness compared to traditional single-modality models, achieving area under the receiver operating characteristic curve values of 0.884 and 0.854 in external test sets 1 and 2, respectively. The model maintained excellent diagnostic efficacy across both >6 cm and ≤6 cm tumor subgroups. Furthermore, the model-derived risk score successfully stratified metastasis-free survival in the overall cohort (P < 0.001) and the clinically ambiguous ≤6 cm subgroup (P = 0.003), serving as an independent prognostic factor (HR = 10.73, P = 0.028).

CONCLUSION

The fusion model is a robust, non-invasive tool for preoperatively identifying high-risk PPGLs. Particularly for tumors ≤6 cm where decision-making is challenging, it provides objective evidence to individualize surgical strategies and stratify postoperative surveillance.