Independent Testing of Published CT Models for PD-L1 Status in Non-Small Cell Lung Cancer.

Background With the shift toward perioperative programmed cell death protein-1 and programmed cell death ligand-1 (PD-L1) immunotherapy in non-small cell lung cancer (NSCLC), there is a need to assess PD-L1 status preoperatively. Identifying patients who may benefit from immunotherapy using CT-based features has been hampered by the lack of independent testing. Purpose To evaluate the performance of published CT models in predicting PD-L1 status in a multi-institutional external test set of patients with NSCLC undergoing surgery. Materials and Methods In this retrospective study, published CT radiomic models predicting PD-L1 expression were identified by literature review spanning January 2017 to July 2023. Models with sufficient reporting quality were recreated for testing, using the features and coefficients that were originally published. Feature standardization parameters were trained in a training set, the publicly available NSCLC Cancer Imaging Archive dataset, containing images collected between April 2008 and September 2012, without label observation, for the sole purpose of test set preprocessing. For comparison, one previously published model was also retrained to predict