Independent Validation of the LIONS PREY in Patients Undergoing Navigational Bronchoscopy

INTRODUCTION: Accurate malignancy risk prediction of pulmonary lesions is essential in the context of lung cancer screening and early diagnosis. Widely used risk prediction tools, such as the Brock and Herder models, have shown limited performance in high-risk cohorts referred for bronchoscopic evaluation. The LIONS PREY (lung lesion score predicts malignancy) was specifically developed to provide a simple and reliable estimate of malignancy risk in this clinical setting. This study aimed to externally validate the LIONS PREY model and to compare its predictive performance with the Brock and Herder models in patients undergoing index navigational bronchoscopy for pulmonary lesion evaluation. METHODS: We retrospectively analysed patients who underwent index navigational bronchoscopy for peripheral pulmonary lesions between December 2019 and March 2024 at a tertiary academic centre. Malignancy risk was estimated using the LIONS PREY, Brock, and Herder models. Model performance was assessed via receiver operating characteristic (ROC) analysis and classification accuracy. RESULTS: Among 193 evaluable lesions, 134 (69.4%) were histologically confirmed malignant. Malignant lesions were associated with increased growth dynamics (2.7 ± 4.1 mm vs. 1.0 ± 4.3 mm, p < 0.001) and spiculation (56.0% vs. 23.7%, p < 0.001). The LIONS PREY achieved an area under the ROC curve (AUC) of 0.94, outperforming Herder (AUC 0.72; p < 0.001) and Brock (AUC 0.62; p < 0.001) models. Correct classification rates were highest for LIONS PREY (85.0%) versus Herder (70.3%) and Brock (69.1%) (all p < 0.001). CONCLUSION: The LIONS PREY demonstrated superior predictive accuracy over Brock and Herder in high-risk patients undergoing navigational bronchoscopy, supporting its clinical utility for malignancy risk stratification.