Pretreatment 18F-FDG PET/CT Radiomics for Predicting Response to First-Line Targeted Therapy Plus Immunotherapy in Metastatic Renal Cell Carcinoma

This single-center retrospective observational study evaluates whether quantitative imaging features from pretreatment 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) can help predict response to first-line tyrosine kinase inhibitor (TKI) plus immune checkpoint inhibitor (ICI) therapy in patients with metastatic renal cell carcinoma. The study reviews existing medical records and imaging data from 228 patients treated at the First Affiliated Hospital of Fujian Medical University between January 2019 and December 2025. Treatment was selected as part of routine clinical care and was not assigned by the study. Imaging features are extracted separately from the primary kidney tumor and metastatic lesions and are then combined to develop a patient-level multi-lesion radiomics model. Treatment response is assessed according to Response Evaluation Criteria in Solid Tumors version 1.1 approximately 12 weeks after treatment initiation. Complete response or partial response is classified as response, whereas stable disease or progressive disease is classified as non-response. The study compares imaging-based, clinical, and combined prediction models and also evaluates their association with progression-free survival.