A validated study of 612 patients found that adding delayed-phase 18F-FDG PET/CT to prediction models for indeterminate pulmonary nodules delivered only marginal gains, with calibration issues and sensitivity–specificity trade-offs (ID: 1ba813d1d2ebffcd). The results suggest delayed imaging may not materially improve clinical decision-making. The work adds to the ongoing push for more discriminative biomarkers and robust model calibration in pulmonary nodule pathways, where false positives and misclassification can cascade into unnecessary interventions.